diff --git a/src/application/config/constants.php b/src/application/config/constants.php
index deefe73e..aa44e0a8 100644
--- a/src/application/config/constants.php
+++ b/src/application/config/constants.php
@@ -64,12 +64,12 @@ define('PRIV_ADD', 2);
 define('PRIV_EDIT', 4);
 define('PRIV_DELETE', 8);
 
-define('PAGE_APPOINTMENTS', 'appointments');
-define('PAGE_CUSTOMERS', 'customers');
-define('PAGE_SERVICES', 'services');
-define('PAGE_USERS', 'users');
-define('PAGE_SYSTEM_SETTINGS', 'system_settings');
-define('PAGE_USER_SETTINGS', 'user_settings');
+define('PRIV_APPOINTMENTS', 'appointments');
+define('PRIV_CUSTOMERS', 'customers');
+define('PRIV_SERVICES', 'services');
+define('PRIV_USERS', 'users');
+define('PRIV_SYSTEM_SETTINGS', 'system_settings');
+define('PRIV_USER_SETTINGS', 'user_settings');
 
 define('MIN_PASSWORD_LENGTH', 7);
 /* End of file constants.php */
diff --git a/src/application/controllers/backend.php b/src/application/controllers/backend.php
index ae0fe46a..8994b34f 100644
--- a/src/application/controllers/backend.php
+++ b/src/application/controllers/backend.php
@@ -19,19 +19,22 @@ class Backend extends CI_Controller {
      */
     public function index($appointment_hash = '') {
         $this->session->set_userdata('dest_url', $this->config->item('base_url') . 'backend');
-        if (!$this->hasPrivileges(PAGE_APPOINTMENTS)) return;
+        if (!$this->hasPrivileges(PRIV_APPOINTMENTS)) return;
         
         $this->load->model('appointments_model');
         $this->load->model('providers_model');
         $this->load->model('services_model');
         $this->load->model('customers_model');
         $this->load->model('settings_model');
+        $this->load->model('roles_model');
         
         $view['base_url'] = $this->config->item('base_url');
         $view['book_advance_timeout'] = $this->settings_model->get_setting('book_advance_timeout');
         $view['company_name'] = $this->settings_model->get_setting('company_name');
         $view['available_providers'] = $this->providers_model->get_available_providers();
         $view['available_services'] = $this->services_model->get_available_services();
+        $view['customers'] = $this->customers_model->get_batch();
+        $this->setUserData($view);
         
         if ($appointment_hash != '') {
             $results = $this->appointments_model->get_batch(array('hash' => $appointment_hash));
@@ -54,7 +57,7 @@ class Backend extends CI_Controller {
      */
     public function customers() {
         $this->session->set_userdata('dest_url', $this->config->item('base_url') . 'backend/customers');
-    	if (!$this->hasPrivileges(PAGE_CUSTOMERS)) return;
+    	if (!$this->hasPrivileges(PRIV_CUSTOMERS)) return;
     	
         $this->load->model('providers_model');
         $this->load->model('customers_model');
@@ -66,6 +69,7 @@ class Backend extends CI_Controller {
         $view['customers'] = $this->customers_model->get_batch();
         $view['available_providers'] = $this->providers_model->get_available_providers();
         $view['available_services'] = $this->services_model->get_available_services();
+        $this->setUserData($view);
         
         $this->load->view('backend/header', $view);
         $this->load->view('backend/customers', $view);
@@ -83,7 +87,7 @@ class Backend extends CI_Controller {
      */
     public function services() {
         $this->session->set_userdata('dest_url', $this->config->item('base_url') . 'backend/services');
-        if (!$this->hasPrivileges(PAGE_SERVICES)) return;
+        if (!$this->hasPrivileges(PRIV_SERVICES)) return;
         
         $this->load->model('customers_model');
         $this->load->model('services_model');
@@ -93,6 +97,7 @@ class Backend extends CI_Controller {
         $view['company_name'] = $this->settings_model->get_setting('company_name');
         $view['services'] = $this->services_model->get_batch();
         $view['categories'] = $this->services_model->get_all_categories();
+        $this->setUserData($view);
         
         $this->load->view('backend/header', $view);
         $this->load->view('backend/services', $view);
@@ -108,7 +113,7 @@ class Backend extends CI_Controller {
      */
     public function users() {
         $this->session->set_userdata('dest_url', $this->config->item('base_url') . 'backend/users');
-        if (!$this->hasPrivileges(PAGE_USERS)) return;
+        if (!$this->hasPrivileges(PRIV_USERS)) return;
         
         $this->load->model('providers_model');
         $this->load->model('secretaries_model');
@@ -123,6 +128,7 @@ class Backend extends CI_Controller {
         $view['secretaries'] = $this->secretaries_model->get_batch();
         $view['services'] = $this->services_model->get_batch(); 
         $view['working_plan'] = $this->settings_model->get_setting('company_working_plan');
+        $this->setUserData($view);
         
         $this->load->view('backend/header', $view);
         $this->load->view('backend/users', $view);
@@ -138,8 +144,8 @@ class Backend extends CI_Controller {
      */
     public function settings() {
         $this->session->set_userdata('dest_url', $this->config->item('base_url') . 'backend/settings');
-        if (!$this->hasPrivileges(PAGE_SYSTEM_SETTINGS)
-                && !$this->hasPrivileges(PAGE_USER_SETTINGS)) return;
+        if (!$this->hasPrivileges(PRIV_SYSTEM_SETTINGS, FALSE)
+                && !$this->hasPrivileges(PRIV_USER_SETTINGS)) return;
         
         $this->load->model('settings_model');
         $this->load->model('user_model');
@@ -152,6 +158,7 @@ class Backend extends CI_Controller {
         $view['role_slug'] = $this->session->userdata('role_slug');
         $view['system_settings'] = $this->settings_model->get_settings();
         $view['user_settings'] = $this->user_model->get_settings($user_id);
+        $this->setUserData($view);
         
         $this->load->view('backend/header', $view);
         $this->load->view('backend/settings', $view);
@@ -199,6 +206,21 @@ class Backend extends CI_Controller {
         
         return TRUE;
     }
+    
+    /**
+     * Set the user data in order to be available at the view and js code.
+     * 
+     * @param array $view Contains the view data. 
+     */
+    public function setUserData(&$view) {
+        $this->load->model('roles_model');
+        
+        // Get privileges
+        $view['user_id'] = $this->session->userdata('user_id');
+        $view['user_email'] = $this->session->userdata('user_email');
+        $view['role_slug'] = $this->session->userdata('role_slug');
+        $view['privileges'] = $this->roles_model->get_privileges($this->session->userdata('role_slug'));
+    }
 }
 
 /* End of file backend.php */
diff --git a/src/application/controllers/backend_api.php b/src/application/controllers/backend_api.php
index d1b41fb2..eec38de2 100644
--- a/src/application/controllers/backend_api.php
+++ b/src/application/controllers/backend_api.php
@@ -4,6 +4,17 @@
  * Contains all the backend ajax calls.
  */
 class Backend_api extends CI_Controller {
+    private $privileges;
+    
+    public function __construct() {
+        parent::__construct();
+        
+        $this->load->library('session');
+        $this->load->model('roles_model');
+        $this->privileges = $this->roles_model->get_privileges($this->session->userdata('role_slug'));
+    }
+    
+    
     /**
      * [AJAX] Get the registered appointments for the given date period and record.
      * 
@@ -16,12 +27,16 @@ class Backend_api extends CI_Controller {
      * @param {string} $_POST['end_date'] The user selected end date.
      */
     public function ajax_get_calendar_appointments() {
-        $this->load->model('appointments_model');
-        $this->load->model('providers_model');
-        $this->load->model('services_model');
-        $this->load->model('customers_model');
-        
         try {
+            if ($this->privileges[PRIV_APPOINTMENTS]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
+            $this->load->model('appointments_model');
+            $this->load->model('providers_model');
+            $this->load->model('services_model');
+            $this->load->model('customers_model');
+            
             if ($_POST['filter_type'] == FILTER_TYPE_PROVIDER) {
                 $where_id = 'id_users_provider';
             } else { 
@@ -85,12 +100,28 @@ class Backend_api extends CI_Controller {
             // :: SAVE CUSTOMER CHANGES TO DATABASE
             if (isset($_POST['customer_data'])) {
                 $customer = json_decode(stripcslashes($_POST['customer_data']), true);
+                
+                $REQUIRED_PRIV = (!isset($customer['id'])) 
+                        ? $this->privileges[PRIV_CUSTOMERS]['add'] 
+                        : $this->privileges[PRIV_CUSTOMERS]['edit'];
+                if ($REQUIRED_PRIV == FALSE) {
+                    throw new Exception('You do not have the required privileges for this task.');
+                }
+                
                 $customer['id'] = $this->customers_model->add($customer);
             }
             
         	// :: SAVE APPOINTMENT CHANGES TO DATABASE
             if (isset($_POST['appointment_data'])) {
                 $appointment = json_decode(stripcslashes($_POST['appointment_data']), true);
+                
+                $REQUIRED_PRIV = (!isset($appointment['id'])) 
+                        ? $this->privileges[PRIV_APPOINTMENTS]['add'] 
+                        : $this->privileges[PRIV_APPOINTMENTS]['edit'];
+                if ($REQUIRED_PRIV == FALSE) {
+                    throw new Exception('You do not have the required privileges for this task.');
+                }
+                
                 $manage_mode = isset($appointment['id']);
                 // If the appointment does not contain the customer record id, then it 
                 // means that is is going to be inserted. Get the customer's record id.
@@ -210,6 +241,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_appointment() {    
         try {
+            if ($this->privileges[PRIV_APPOINTMENTS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             if (!isset($_POST['appointment_id'])) {
                 throw new Exception('No appointment id provided.');
             }
@@ -298,6 +333,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_disable_provider_sync() {
         try { 
+            if ($this->privileges[PRIV_USERS]['edit'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             if (!isset($_POST['provider_id'])) {
                 throw new Exception('Provider id not specified.');
             }
@@ -323,6 +362,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_customers() {
     	try {
+            if ($this->privileges[PRIV_CUSTOMERS]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('appointments_model');
             $this->load->model('services_model');
             $this->load->model('providers_model');
@@ -355,8 +398,6 @@ class Backend_api extends CI_Controller {
                 $customer['appointments'] = $appointments;
             }
             
-            
-            
 	    	echo json_encode($customers);
             
     	} catch(Exception $exc) {
@@ -374,13 +415,22 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_save_unavailable() {
         try {
+            // Check privileges
+            $unavailable = json_decode($_POST['unavailable'], true);
+            
+            $REQUIRED_PRIV = (!isset($unavailable['id'])) 
+                    ? $this->privileges[PRIV_APPOINTMENTS]['add'] 
+                    : $this->privileges[PRIV_APPOINTMENTS]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('appointments_model');
             $this->load->model('providers_model');
             
             // Add appointment
-            $unavailable = json_decode($_POST['unavailable'], true);
             $unavailable['id'] = $this->appointments_model->add_unavailable($unavailable); 
-            $unavailable = $this->appointments_model->get_row($unavailable['id']);
+            $unavailable = $this->appointments_model->get_row($unavailable['id']); // fetch all inserted data
             
             // Google Sync
             try {
@@ -428,6 +478,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_unavailable() {
         try {
+            if ($this->privileges[PRIV_APPOINTMENTS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('appointments_model');
             $this->load->model('providers_model');
             
@@ -474,6 +528,14 @@ class Backend_api extends CI_Controller {
         try {
             $this->load->model('customers_model');
             $customer = json_decode($_POST['customer'], true);
+            
+            $REQUIRED_PRIV = (!isset($customer['id'])) 
+                    ? $this->privileges[PRIV_CUSTOMERS]['add'] 
+                    : $this->privileges[PRIV_CUSTOMERS]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $customer_id = $this->customers_model->add($customer);
             echo json_encode(array(
                 'status' => AJAX_SUCCESS,
@@ -493,6 +555,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_customer() {
         try {
+            if ($this->privileges[PRIV_CUSTOMERS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('customers_model');
             $this->customers_model->delete($_POST['customer_id']);
             echo json_encode(AJAX_SUCCESS);
@@ -512,6 +578,14 @@ class Backend_api extends CI_Controller {
         try {
             $this->load->model('services_model');
             $service = json_decode($_POST['service'], true);
+            
+            $REQUIRED_PRIV = (!isset($service['id'])) 
+                    ? $this->privileges[PRIV_SERVICES]['add'] 
+                    : $this->privileges[PRIV_SERVICES]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $service_id =$this->services_model->add($service);
             echo json_encode(array(
                 'status' => AJAX_SUCCESS,
@@ -531,6 +605,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_service() {
         try {
+            if ($this->privileges[PRIV_SERVICES]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('services_model');
             $result = $this->services_model->delete($_POST['service_id']);
             echo ($result) ? json_encode(AJAX_SUCCESS) : json_encode(AJAX_FAILURE);
@@ -549,6 +627,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_services() {
         try {
+            if ($this->privileges[PRIV_SERVICES]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('services_model');
             $key = mysql_real_escape_string($_POST['key']);  
             $where = 
@@ -574,6 +656,14 @@ class Backend_api extends CI_Controller {
         try {
             $this->load->model('services_model');
             $category = json_decode($_POST['category'], true);
+            
+            $REQUIRED_PRIV = (!isset($category['id'])) 
+                    ? $this->privileges[PRIV_SERVICES]['add'] 
+                    : $this->privileges[PRIV_SERVICES]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $category_id = $this->services_model->add_category($category);
             echo json_encode(array(
                 'status' => AJAX_SUCCESS,
@@ -593,6 +683,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_service_category() {
         try {
+            if ($this->privileges[PRIV_SERVICES]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('services_model');
             $result = $this->services_model->delete_category($_POST['category_id']);
             echo ($result) ? json_encode(AJAX_SUCCESS) : json_encode(AJAX_FAILURE);
@@ -611,6 +705,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_service_categories() {
         try {
+            if ($this->privileges[PRIV_SERVICES]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('services_model');
             $key = mysql_real_escape_string($_POST['key']);  
             $where = '(name LIKE "%' . $key . '%" OR description LIKE "%' . $key . '%")';
@@ -631,6 +729,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_admins() {
         try {
+            if ($this->privileges[PRIV_USERS]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('admins_model');
             $key = mysql_real_escape_string($_POST['key']); 
             $where = 
@@ -660,6 +762,14 @@ class Backend_api extends CI_Controller {
         try {
             $this->load->model('admins_model');
             $admin = json_decode($_POST['admin'], true);
+            
+            $REQUIRED_PRIV = (!isset($admin['id'])) 
+                    ? $this->privileges[PRIV_USERS]['add'] 
+                    : $this->privileges[PRIV_USERS]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $admin_id = $this->admins_model->add($admin);
             
             $response = array(
@@ -683,6 +793,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_admin() {
         try {
+            if ($this->privileges[PRIV_USERS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('admins_model');
             $result = $this->admins_model->delete($_POST['admin_id']);
             echo ($result) ? json_encode(AJAX_SUCCESS) : json_encode(AJAX_FAILURE);
@@ -701,6 +815,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_providers() {
         try {
+            if ($this->privileges[PRIV_USERS]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('providers_model');
             $key = mysql_real_escape_string($_POST['key']); 
             $where = 
@@ -731,6 +849,13 @@ class Backend_api extends CI_Controller {
             $this->load->model('providers_model');
             $provider = json_decode($_POST['provider'], true);
             
+            $REQUIRED_PRIV = (!isset($provider['id'])) 
+                    ? $this->privileges[PRIV_USERS]['add'] 
+                    : $this->privileges[PRIV_USERS]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             if (!isset($provider['settings']['working_plan'])) {
                 $this->load->model('settings_model');
                 $provider['settings']['working_plan'] = $this->settings_model
@@ -759,6 +884,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_provider() {
         try {
+            if ($this->privileges[PRIV_USERS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('providers_model');
             $result = $this->providers_model->delete($_POST['provider_id']);
             echo ($result) ? json_encode(AJAX_SUCCESS) : json_encode(AJAX_FAILURE);
@@ -777,6 +906,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_filter_secretaries() {
         try {
+            if ($this->privileges[PRIV_USERS]['view'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('secretaries_model');
             $key = mysql_real_escape_string($_POST['key']); 
             $where = 
@@ -806,6 +939,14 @@ class Backend_api extends CI_Controller {
         try {
             $this->load->model('secretaries_model');
             $secretary = json_decode($_POST['secretary'], true);
+            
+            $REQUIRED_PRIV = (!isset($secretary['id'])) 
+                    ? $this->privileges[PRIV_USERS]['add']
+                    : $this->privileges[PRIV_USERS]['edit'];
+            if ($REQUIRED_PRIV == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $secretary_id = $this->secretaries_model->add($secretary);
             
             echo json_encode(array(
@@ -827,6 +968,10 @@ class Backend_api extends CI_Controller {
      */
     public function ajax_delete_secretary() {
         try {
+            if ($this->privileges[PRIV_USERS]['delete'] == FALSE) {
+                throw new Exception('You do not have the required privileges for this task.');
+            }
+            
             $this->load->model('secretaries_model');
             $result = $this->secretaries_model->delete($_POST['secretary_id']);
             echo ($result) ? json_encode(AJAX_SUCCESS) : json_encode(AJAX_FAILURE);
@@ -850,10 +995,16 @@ class Backend_api extends CI_Controller {
     public function ajax_save_settings() {
         try {
             if ($_POST['type'] == SETTINGS_SYSTEM) {
+                if ($this->privileges[PRIV_SYSTEM_SETTINGS]['edit'] == FALSE) {
+                    throw new Exception('You do not have the required privileges for this task.');
+                }
                 $this->load->model('settings_model');
                 $settings = json_decode($_POST['settings'], true);
                 $this->settings_model->save_settings($settings);
             } else if ($_POST['type'] == SETTINGS_USER) {
+                if ($this->privileges[PRIV_USER_SETTINGS]['edit'] == FALSE) {
+                    throw new Exception('You do not have the required privileges for this task.');
+                }
                 $this->load->model('user_model');
                 $this->user_model->save_settings(json_decode($_POST['settings'], true));
             }
diff --git a/src/application/controllers/user.php b/src/application/controllers/user.php
index 4966930f..138706da 100644
--- a/src/application/controllers/user.php
+++ b/src/application/controllers/user.php
@@ -38,11 +38,18 @@ class User extends CI_Controller {
     }
     
     public function no_privileges() {
-        // can't view the requested page.
+        $view['base_url'] = $this->config->item('base_url');
+        $this->load->view('user/no_privileges', $view);
     }
     
     /**
      * [AJAX] Check whether the user has entered the correct login credentials.
+     * 
+     * The session data of a logged in user are the following:
+     *      'user_id'
+     *      'user_email'
+     *      'role_slug'
+     *      'dest_url'
      */
     public function ajax_check_login() {
         try {
diff --git a/src/application/models/admins_model.php b/src/application/models/admins_model.php
index ca249818..3fbe331b 100644
--- a/src/application/models/admins_model.php
+++ b/src/application/models/admins_model.php
@@ -35,9 +35,7 @@ class Admins_Model extends CI_Model {
      * @throws Exception When the admin data are invalid (see validate() method).
      */
     public function add($admin) {
-        if (!$this->validate($admin)) {
-            throw new Exception('Admin data are invalid: ' . print_r($admin, TRUE));
-        }
+        $this->validate($admin);
         
         if ($this->exists($admin) && !isset($admin['id'])) {
             $admin['id'] = $this->find_record_id($admin);
@@ -178,44 +176,42 @@ class Admins_Model extends CI_Model {
      * 
      * @param array $admin Contains the admin user data.
      * @return bool Returns the validation result.
+     * 
+     * @throws Exception When data are invalid.
      */
     public function validate($admin) {
         $this->load->helper('data_validation');
-        
-        try {
-            // If a record id is provided then check whether the record exists in the database.
-            if (isset($admin['id'])) {
-                $num_rows = $this->db->get_where('ea_users', array('id' => $admin['id']))
-                        ->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Given admin id does not exist in database: ' . $admin['id']);
-                }
+
+        // If a record id is provided then check whether the record exists in the database.
+        if (isset($admin['id'])) {
+            $num_rows = $this->db->get_where('ea_users', array('id' => $admin['id']))
+                    ->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Given admin id does not exist in database: ' . $admin['id']);
             }
-            
-            // Validate required fields integrity.
-            if (!isset($admin['last_name'])
-                    || !isset($admin['email'])
-                    || !isset($admin['phone_number'])) { 
-                throw new Exception('Not all required fields are provided : ' . print_r($admin, TRUE));
-            }
-            
-            // Validate admin email address.
-            if (!filter_var($admin['email'], FILTER_VALIDATE_EMAIL)) {
-                throw new Exception('Invalid email address provided : ' . $admin['email']);
-            }
-            
-            // Validate admin password
-            if (isset($admin['settings']['password'])) {
-                if (strlen($admin['settings']['password']) < MIN_PASSWORD_LENGTH) {
-                    throw new Exception('The user password must be at least ' 
-                            . MIN_PASSWORD_LENGTH . ' characters long.');
-                }
-            }
-            
-            return TRUE;
-        } catch (Exception $exc) {
-            return FALSE;
         }
+
+        // Validate required fields integrity.
+        if (!isset($admin['last_name'])
+                || !isset($admin['email'])
+                || !isset($admin['phone_number'])) { 
+            throw new Exception('Not all required fields are provided : ' . print_r($admin, TRUE));
+        }
+
+        // Validate admin email address.
+        if (!filter_var($admin['email'], FILTER_VALIDATE_EMAIL)) {
+            throw new Exception('Invalid email address provided : ' . $admin['email']);
+        }
+
+        // Validate admin password
+        if (isset($admin['settings']['password'])) {
+            if (strlen($admin['settings']['password']) < MIN_PASSWORD_LENGTH) {
+                throw new Exception('The user password must be at least ' 
+                        . MIN_PASSWORD_LENGTH . ' characters long.');
+            }
+        }
+            
+        return TRUE; // Operation completed successfully.
     }
     
     /**
diff --git a/src/application/models/appointments_model.php b/src/application/models/appointments_model.php
index 01518421..98f14837 100644
--- a/src/application/models/appointments_model.php
+++ b/src/application/models/appointments_model.php
@@ -21,9 +21,7 @@ class Appointments_Model extends CI_Model {
      */
     public function add($appointment) {
         // Validate the appointment data before doing anything.
-        if (!$this->validate($appointment)) {
-            throw new Exception('Appointment data are invalid.');
-        }
+        $this->validate($appointment);
         
         // Perform insert() or update() operation.
         if (!isset($appointment['id'])) {
@@ -148,64 +146,60 @@ class Appointments_Model extends CI_Model {
     public function validate($appointment) {
         $this->load->helper('data_validation');
         
-        try {
-            // If a appointment id is given, check wether the record exists
-            // in the database.
-            if (isset($appointment['id'])) {
-                $num_rows = $this->db->get_where('ea_appointments', 
-                        array('id' => $appointment['id']))->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Provided appointment id does not '
-                            . 'exist in the database.');
-                }
-            }
-            
-            // Check if appointment dates are valid.
-            if (!validate_mysql_datetime($appointment['start_datetime'])) {
-                throw new Exception('Appointment start datetime is invalid.');    
-            }
-            
-            if (!validate_mysql_datetime($appointment['end_datetime'])) {
-                throw new Exception('Appointment end datetime is invalid.');
+        // If a appointment id is given, check wether the record exists
+        // in the database.
+        if (isset($appointment['id'])) {
+            $num_rows = $this->db->get_where('ea_appointments', 
+                    array('id' => $appointment['id']))->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Provided appointment id does not '
+                        . 'exist in the database.');
             }
+        }
 
-            // Check if the provider's id is valid. 
+        // Check if appointment dates are valid.
+        if (!validate_mysql_datetime($appointment['start_datetime'])) {
+            throw new Exception('Appointment start datetime is invalid.');    
+        }
+
+        if (!validate_mysql_datetime($appointment['end_datetime'])) {
+            throw new Exception('Appointment end datetime is invalid.');
+        }
+
+        // Check if the provider's id is valid. 
+        $num_rows = $this->db
+                ->select('*')
+                ->from('ea_users')
+                ->join('ea_roles', 'ea_roles.id = ea_users.id_roles', 'inner')
+                ->where('ea_users.id', $appointment['id_users_provider'])
+                ->where('ea_roles.slug', DB_SLUG_PROVIDER)
+                ->get()->num_rows();
+        if ($num_rows == 0) {
+            throw new Exception('Appointment provider id is invalid.');
+        }
+
+        if ($appointment['is_unavailable'] == FALSE) { 
+            // Check if the customer's id is valid.
             $num_rows = $this->db
                     ->select('*')
                     ->from('ea_users')
                     ->join('ea_roles', 'ea_roles.id = ea_users.id_roles', 'inner')
-                    ->where('ea_users.id', $appointment['id_users_provider'])
-                    ->where('ea_roles.slug', DB_SLUG_PROVIDER)
+                    ->where('ea_users.id', $appointment['id_users_customer'])
+                    ->where('ea_roles.slug', DB_SLUG_CUSTOMER)
                     ->get()->num_rows();
             if ($num_rows == 0) {
-                throw new Exception('Appointment provider id is invalid.');
+                throw new Exception('Appointment customer id is invalid.');
             }
-            
-            if ($appointment['is_unavailable'] == FALSE) { 
-                // Check if the customer's id is valid.
-                $num_rows = $this->db
-                        ->select('*')
-                        ->from('ea_users')
-                        ->join('ea_roles', 'ea_roles.id = ea_users.id_roles', 'inner')
-                        ->where('ea_users.id', $appointment['id_users_customer'])
-                        ->where('ea_roles.slug', DB_SLUG_CUSTOMER)
-                        ->get()->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Appointment customer id is invalid.');
-                }
-                
-                // Check if the service id is valid.
-                $num_rows = $this->db->get_where('ea_services', 
-                        array('id' => $appointment['id_services']))->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Appointment customer id is invalid.');
-                }
+
+            // Check if the service id is valid.
+            $num_rows = $this->db->get_where('ea_services', 
+                    array('id' => $appointment['id_services']))->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Appointment customer id is invalid.');
             }
-            
-            return TRUE;
-        } catch (Exception $exc) {
-            return FALSE;
         }
+
+        return TRUE;
     }
     
     /**
diff --git a/src/application/models/customers_model.php b/src/application/models/customers_model.php
index ae2c7a25..220623c0 100644
--- a/src/application/models/customers_model.php
+++ b/src/application/models/customers_model.php
@@ -21,9 +21,7 @@ class Customers_Model extends CI_Model {
      */
     public function add($customer) {
         // Validate the customer data before doing anything.
-        if (!$this->validate($customer)) {
-            throw new Exception('Customer data are not valid.');
-        }
+        !$this->validate($customer);
         
         // :: CHECK IF CUSTOMER ALREADY EXIST (FROM EMAIL).	
         if ($this->exists($customer) && !isset($customer['id'])) {
@@ -158,35 +156,32 @@ class Customers_Model extends CI_Model {
     public function validate($customer) {
         $this->load->helper('data_validation');
         
-        try {
-            // If a customer id is provided, check whether the record
-            // exist in the database.
-            if (isset($customer['id'])) {
-                $num_rows = $this->db->get_where('ea_users', 
-                        array('id' => $customer['id']))->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Provided customer id does not ' 
-                            . 'exist in the database.');
-                }
+        
+        // If a customer id is provided, check whether the record
+        // exist in the database.
+        if (isset($customer['id'])) {
+            $num_rows = $this->db->get_where('ea_users', 
+                    array('id' => $customer['id']))->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Provided customer id does not ' 
+                        . 'exist in the database.');
             }
-            // Validate required fields
-            if (!isset($customer['last_name'])
-                    || !isset($customer['email'])
-                    || !isset($customer['phone_number'])) { 
-                throw new Exception('Not all required fields are provided : ' 
-                        . print_r($customer, TRUE));
-            }
-            
-            // Validate email address
-            if (!filter_var($customer['email'], FILTER_VALIDATE_EMAIL)) {
-                throw new Exception('Invalid email address provided : ' 
-                        . $customer['email']);
-            }
-            
-            return TRUE;
-        } catch (Exception $exc) {
-            return FALSE;
         }
+        // Validate required fields
+        if (!isset($customer['last_name'])
+                || !isset($customer['email'])
+                || !isset($customer['phone_number'])) { 
+            throw new Exception('Not all required fields are provided : ' 
+                    . print_r($customer, TRUE));
+        }
+
+        // Validate email address
+        if (!filter_var($customer['email'], FILTER_VALIDATE_EMAIL)) {
+            throw new Exception('Invalid email address provided : ' 
+                    . $customer['email']);
+        }
+
+        return TRUE;
     }
     
     /**
diff --git a/src/application/models/providers_model.php b/src/application/models/providers_model.php
index 0e49ed06..2a8813f6 100644
--- a/src/application/models/providers_model.php
+++ b/src/application/models/providers_model.php
@@ -48,9 +48,7 @@ class Providers_Model extends CI_Model {
      * @throws Exception When the record data validation fails.
      */
     public function add($provider) {
-        if (!$this->validate($provider)) {
-            throw new Exception('Provider data are not valid :' . print_r($provider, TRUE));
-        }
+        $this->validate($provider);
         
         if ($this->exists($provider) && !isset($provider['id'])) {
             $provider['id'] = $this->find_record_id($provider);
@@ -196,58 +194,54 @@ class Providers_Model extends CI_Model {
     public function validate($provider) {
         $this->load->helper('data_validation');
         
-        try {
-            // If a provider id is present, check whether the record exist in the database.
-            if (isset($provider['id'])) {
-                $num_rows = $this->db->get_where('ea_users', 
-                        array('id' => $provider['id']))->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Provided record id does not exist in the database.');
-                }
+        // If a provider id is present, check whether the record exist in the database.
+        if (isset($provider['id'])) {
+            $num_rows = $this->db->get_where('ea_users', 
+                    array('id' => $provider['id']))->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Provided record id does not exist in the database.');
             }
-            
-            // Validate required fields.
-            if (!isset($provider['last_name'])
-                    || !isset($provider['email'])
-                    || !isset($provider['phone_number'])) { 
-                throw new Exception('Not all required fields are provided : ' . print_r($provider, TRUE));
-            }
-            
-            // Validate provider email address.
-            if (!filter_var($provider['email'], FILTER_VALIDATE_EMAIL)) {
-                throw new Exception('Invalid email address provided : ' . $provider['email']);
-            }
-            
-            // Validate provider services.
-            if (!isset($provider['services']) || !is_array($provider['services'])) {
-                throw new Exception('Invalid provider services given: ' . print_r($provider, TRUE));
-            } else { // Check if services are valid numeric values.
-                foreach($provider['services'] as $service_id) {
-                    if (!is_numeric($service_id)) {
-                        throw new Exception('A provider service with invalid id was found: ' 
-                                . print_r($provider, TRUE));
-                    }
-                }
-            }
-            
-            // Validate provider settings.
-            if (!isset($provider['settings']) || count($provider['settings']) == 0
-                    || !is_array($provider['settings'])) {
-                throw new Exception('Invalid provider settings given: ' . print_r($provider, TRUE));
-            }
-            
-            // Validate admin password
-            if (isset($provider['settings']['password'])) {
-                if (strlen($provider['settings']['password']) < MIN_PASSWORD_LENGTH) {
-                    throw new Exception('The user password must be at least ' 
-                            . MIN_PASSWORD_LENGTH . ' characters long.');
-                }
-            }
-            
-            return TRUE;
-        } catch (Exception $exc) {
-            return FALSE;
         }
+
+        // Validate required fields.
+        if (!isset($provider['last_name'])
+                || !isset($provider['email'])
+                || !isset($provider['phone_number'])) { 
+            throw new Exception('Not all required fields are provided : ' . print_r($provider, TRUE));
+        }
+
+        // Validate provider email address.
+        if (!filter_var($provider['email'], FILTER_VALIDATE_EMAIL)) {
+            throw new Exception('Invalid email address provided : ' . $provider['email']);
+        }
+
+        // Validate provider services.
+        if (!isset($provider['services']) || !is_array($provider['services'])) {
+            throw new Exception('Invalid provider services given: ' . print_r($provider, TRUE));
+        } else { // Check if services are valid numeric values.
+            foreach($provider['services'] as $service_id) {
+                if (!is_numeric($service_id)) {
+                    throw new Exception('A provider service with invalid id was found: ' 
+                            . print_r($provider, TRUE));
+                }
+            }
+        }
+
+        // Validate provider settings.
+        if (!isset($provider['settings']) || count($provider['settings']) == 0
+                || !is_array($provider['settings'])) {
+            throw new Exception('Invalid provider settings given: ' . print_r($provider, TRUE));
+        }
+
+        // Validate admin password
+        if (isset($provider['settings']['password'])) {
+            if (strlen($provider['settings']['password']) < MIN_PASSWORD_LENGTH) {
+                throw new Exception('The user password must be at least ' 
+                        . MIN_PASSWORD_LENGTH . ' characters long.');
+            }
+        }
+
+        return TRUE;
     }
     
     /**
diff --git a/src/application/models/roles_model.php b/src/application/models/roles_model.php
index 556286ac..955522ef 100644
--- a/src/application/models/roles_model.php
+++ b/src/application/models/roles_model.php
@@ -18,6 +18,55 @@ class Roles_Model extends CI_Model {
     public function get_role_id($role_slug) {
         return $this->db->get_where('ea_roles', array('slug' => $role_slug))->row()->id;
     }
+    
+    /**
+     * Returns all the privileges (bool values) of a role slug.
+     * 
+     * The privilege numbers are converted into bool values of the four main actions (view,
+     * add, edit, delete). By checking each value you can know if the user is able to perform
+     * this action.
+     * 
+     * @param string $slug The role slug.
+     * @return array Returns the privilege value.
+     */
+    public function get_privileges($slug) {
+        $privileges = $this->db->get_where('ea_roles', array('slug' => $slug))->row_array();
+        unset($privileges['id'], $privileges['name'], $privileges['slug'], $privileges['is_admin']);
+        
+        // Convert the numeric values to bool so that is easier to check whether a 
+        // user has the required privileges for a specific action.
+        foreach($privileges as &$value) {      
+            $privileges_number = $value; 
+            
+            $value = array(
+                'view' => false,
+                'add' => false,
+                'edit' => false,
+                'delete' => false
+            );
+            
+            if ($privileges_number > 0) {
+                if (intval($privileges_number / PRIV_DELETE) == 1) {
+                    $value['delete'] = TRUE;
+                    $privileges_number -= PRIV_DELETE;
+                }
+
+                if (intval($privileges_number / PRIV_EDIT) == 1) {
+                    $value['edit'] = TRUE;
+                    $privileges_number -= PRIV_EDIT;
+                }
+
+                if (intval($privileges_number / PRIV_ADD) == 1) {
+                    $value['add'] = TRUE;
+                    $privileges_number -= PRIV_ADD;
+                }
+
+                $value['view'] = TRUE;
+            }   
+        }
+        
+        return $privileges;
+    }
 }
 
 /* End of file roles_model.php */
diff --git a/src/application/models/secretaries_model.php b/src/application/models/secretaries_model.php
index 28254f87..8a9f904f 100644
--- a/src/application/models/secretaries_model.php
+++ b/src/application/models/secretaries_model.php
@@ -36,9 +36,7 @@ class Secretaries_Model extends CI_Model {
      * @throws Exception When the secretary data are invalid (see validate() method).
      */
     public function add($secretary) {
-        if (!$this->validate($secretary)) {
-            throw new Exception('Secretary data are invalid: ' . print_r($secretary, TRUE));
-        }
+        $this->validate($secretary);
 
         if ($this->exists($secretary) && !isset($secretary['id'])) {
             $secretary['id'] = $this->find_record_id($secretary);
@@ -177,45 +175,41 @@ class Secretaries_Model extends CI_Model {
     public function validate($secretary) {
         $this->load->helper('data_validation');
         
-        try {
-            // If a record id is provided then check whether the record exists in the database.
-            if (isset($secretary['id'])) {
-                $num_rows = $this->db->get_where('ea_users', array('id' => $secretary['id']))
-                        ->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Given secretary id does not exist in database: ' . $secretary['id']);
-                }
+        // If a record id is provided then check whether the record exists in the database.
+        if (isset($secretary['id'])) {
+            $num_rows = $this->db->get_where('ea_users', array('id' => $secretary['id']))
+                    ->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Given secretary id does not exist in database: ' . $secretary['id']);
             }
-            
-            // Validate 'providers' value datatype (must be array)
-            if (isset($secretary['providers']) && !is_array($secretary['providers'])) {
-                throw new Exception('Secretary providers value is not an array.');
-            }
-            
-            // Validate required fields integrity.
-            if (!isset($secretary['last_name'])
-                    || !isset($secretary['email'])
-                    || !isset($secretary['phone_number'])) { 
-                throw new Exception('Not all required fields are provided : ' . print_r($secretary, TRUE));
-            }
-            
-            // Validate secretary email address.
-            if (!filter_var($secretary['email'], FILTER_VALIDATE_EMAIL)) {
-                throw new Exception('Invalid email address provided : ' . $secretary['email']);
-            }
-            
-            // Validate admin password
-            if (isset($secretary['settings']['password'])) {
-                if (strlen($secretary['settings']['password']) < MIN_PASSWORD_LENGTH) {
-                    throw new Exception('The user password must be at least ' 
-                            . MIN_PASSWORD_LENGTH . ' characters long.');
-                }
-            }
-            
-            return TRUE;
-        } catch (Exception $exc) {
-            return FALSE;
         }
+
+        // Validate 'providers' value datatype (must be array)
+        if (isset($secretary['providers']) && !is_array($secretary['providers'])) {
+            throw new Exception('Secretary providers value is not an array.');
+        }
+
+        // Validate required fields integrity.
+        if (!isset($secretary['last_name'])
+                || !isset($secretary['email'])
+                || !isset($secretary['phone_number'])) { 
+            throw new Exception('Not all required fields are provided : ' . print_r($secretary, TRUE));
+        }
+
+        // Validate secretary email address.
+        if (!filter_var($secretary['email'], FILTER_VALIDATE_EMAIL)) {
+            throw new Exception('Invalid email address provided : ' . $secretary['email']);
+        }
+
+        // Validate admin password
+        if (isset($secretary['settings']['password'])) {
+            if (strlen($secretary['settings']['password']) < MIN_PASSWORD_LENGTH) {
+                throw new Exception('The user password must be at least ' 
+                        . MIN_PASSWORD_LENGTH . ' characters long.');
+            }
+        }
+
+        return TRUE;
     }
     
     /**
diff --git a/src/application/models/services_model.php b/src/application/models/services_model.php
index 6d3903cf..748a869e 100644
--- a/src/application/models/services_model.php
+++ b/src/application/models/services_model.php
@@ -15,9 +15,7 @@ class Services_Model extends CI_Model {
      * @return numeric Returns the record id.
      */
     public function add($service) {
-        if (!$this->validate($service)) {
-            throw new Exception('Service data are invalid.');
-        }
+        $this->validate($service);
         
         if (!isset($service['id'])) {
             $service['id'] = $this->insert($service);
@@ -86,49 +84,45 @@ class Services_Model extends CI_Model {
     public function validate($service) {
         $this->load->helper('data_validation');
         
-        try {
-            // If record id is provided we need to check whether the record exists
-            // in the database.
-            if (isset($service['id'])) {
-                $num_rows = $this->db->get_where('ea_services', array('id' => $service['id']))
-                        ->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Provided service id does not exist in the database.');
-                }
+        // If record id is provided we need to check whether the record exists
+        // in the database.
+        if (isset($service['id'])) {
+            $num_rows = $this->db->get_where('ea_services', array('id' => $service['id']))
+                    ->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Provided service id does not exist in the database.');
             }
-            
-            // Check if service category id is valid (only when present)
-            if ($service['id_service_categories'] != NULL) {
-                $num_rows = $this->db->get_where('ea_service_categories', 
-                        array('id' => $service['id_service_categories']))->num_rows();
-                if ($num_rows == 0) {
-                    throw new Exception('Provided service category id does not exist in database.');
-                }
-            }
-            
-            // Check for required fields
-            if ($service['name'] == '') {
-                throw new Exception('Not all required service fields where provided: ' 
-                        . print_r($service, TRUE));
-            }
-            
-            // Duration must be numeric
-            if ($service['duration'] !== NULL) {
-                if (!is_numeric($service['duration'])) {
-                    throw new Exception('Service duration is not numeric.');
-                }
-            }
-            
-            if ($service['price'] !== NULL) {
-                if (!is_numeric($service['price'])) {
-                    throw new Exception('Service price is not numeric.');
-                }
-            }
-            
-            return TRUE;
-        } catch(Exception $exc) {
-            return FALSE;
         }
+
+        // Check if service category id is valid (only when present)
+        if ($service['id_service_categories'] != NULL) {
+            $num_rows = $this->db->get_where('ea_service_categories', 
+                    array('id' => $service['id_service_categories']))->num_rows();
+            if ($num_rows == 0) {
+                throw new Exception('Provided service category id does not exist in database.');
+            }
+        }
+
+        // Check for required fields
+        if ($service['name'] == '') {
+            throw new Exception('Not all required service fields where provided: ' 
+                    . print_r($service, TRUE));
+        }
+
+        // Duration must be numeric
+        if ($service['duration'] !== NULL) {
+            if (!is_numeric($service['duration'])) {
+                throw new Exception('Service duration is not numeric.');
+            }
+        }
+
+        if ($service['price'] !== NULL) {
+            if (!is_numeric($service['price'])) {
+                throw new Exception('Service price is not numeric.');
+            }
+        }
+
+        return TRUE;
     }
     
     /**
diff --git a/src/application/views/backend/calendar.php b/src/application/views/backend/calendar.php
index fba193f8..97b3ab8f 100644
--- a/src/application/views/backend/calendar.php
+++ b/src/application/views/backend/calendar.php
@@ -16,7 +16,14 @@
         'availableServices'     : <?php echo json_encode($available_services); ?>,
         'baseUrl'               : <?php echo '"' . $base_url . '"'; ?>,
         'bookAdvanceTimeout'    : <?php echo $book_advance_timeout; ?>,
-        'editAppointment'       : <?php echo json_encode($edit_appointment); ?>
+        'editAppointment'       : <?php echo json_encode($edit_appointment); ?>,
+        'customers'             : <?php echo json_encode($customers); ?>,
+        'user'                  : {
+            'id'        : <?php echo $user_id; ?>,
+            'email'     : <?php echo '"' . $user_email . '"'; ?>,
+            'role_slug' : <?php echo '"' . $role_slug . '"'; ?>,
+            'privileges': <?php echo json_encode($privileges); ?>
+        }
     };
     
     $(document).ready(function() {
@@ -33,6 +40,7 @@
         
         <div id="calendar-actions">
             <div class="btn-group">
+                <?php if ($privileges[PRIV_USERS]['edit'] == TRUE) { ?>
                 <button id="google-sync" class="btn btn-primary" 
                         title="Trigger the Google Calendar synchronization process.">
                     <i class="icon-refresh icon-white"></i>
@@ -44,6 +52,7 @@
                     <i class="icon-calendar"></i>
                     <span>Enable Sync</span>
                 </button>
+                <?php } ?>
                 
                 <button id="reload-appointments" class="btn" title="Reload calendar appointments.">
                     <i class="icon-repeat"></i>
@@ -51,19 +60,21 @@
                 </button>
             </div>
             
+            <?php if ($privileges[PRIV_APPOINTMENTS]['add'] == TRUE) { ?>
             <div class="btn-group">
-                <button id="insert-appointment" class="btn" 
+                <button id="insert-appointment" class="btn btn-info" 
                         title="Create a new appointment and store it into the database.">
-                    <i class="icon-plus"></i>
+                    <i class="icon-plus icon-white"></i>
                     <span>Appointment</span>
                 </button>
 
                 <button id="insert-unavailable" class="btn" 
                         title="During unavailable periods the provider won't accept new appointments.">
-                    <i class="icon-ban-circle"></i>
+                    <i class="icon-plus"></i>
                     <span>Unavailable</span>
                 </button>
             </div>
+            <?php } ?>
         </div>
     </div>
     
@@ -75,9 +86,10 @@
         <button type="button" class="close" data-dismiss="modal" 
                 aria-hidden="true">&times;</button>
         <h3>Edit Appointment</h3>
-        <div id="modal-message" class="alert" style="display: none;"></div>
     </div>
     
+    <div class="modal-message alert" style="display: none;"></div>
+    
     <div class="modal-body">
         <form class="form-horizontal">
             <fieldset>
@@ -115,7 +127,14 @@
             </fieldset>
 
             <fieldset class="row-fluid">
-                <legend>Customer Details</legend>
+                <legend>
+                    Customer Details
+                    <button id="select-customer" class="btn btn-primary btn-mini" 
+                            title="Pick an existing customer." type="button">Select Existing Customer</button>
+                    <input type="text" id="filter-existing-customers" placeholder="Type to filter customers." 
+                           style="display: none;" class="input-medium"/>
+                    <div id="existing-customers-list" style="display: none;"></div>
+                </legend>
 
                 <input id="customer-id" type="hidden" />
                 
@@ -192,9 +211,11 @@
         <button type="button" class="close" data-dismiss="modal" 
                 aria-hidden="true">&times;</button>
         <h3>Add Unavailable Period</h3>
-        <div class="modal-message" class="alert" style="display: none;"></div>
+        
     </div>
     
+    <div class="modal-message alert" style="display: none;"></div>
+    
     <div class="modal-body">
         <form class="form-horizontal">
             <fieldset>
diff --git a/src/application/views/backend/customers.php b/src/application/views/backend/customers.php
index 60b88828..d7011816 100644
--- a/src/application/views/backend/customers.php
+++ b/src/application/views/backend/customers.php
@@ -9,7 +9,13 @@
         'availableProviders': <?php echo json_encode($available_providers); ?>,
         'availableServices': <?php echo json_encode($available_services); ?>,
         'baseUrl': <?php echo '"' . $base_url . '"'; ?>,
-        'customers': <?php echo json_encode($customers); ?>
+        'customers': <?php echo json_encode($customers); ?>,
+        'user'                  : {
+            'id'        : <?php echo $user_id; ?>,
+            'email'     : <?php echo '"' . $user_email . '"'; ?>,
+            'role_slug' : <?php echo '"' . $role_slug . '"'; ?>,
+            'privileges': <?php echo json_encode($privileges); ?>
+        }
     };
     
     $(document).ready(function() {
@@ -38,15 +44,23 @@
 	<div id="details" class="span7 row-fluid">
         <div class="btn-toolbar">
             <div id="add-edit-delete-group" class="btn-group">
+                <?php if ($privileges[PRIV_CUSTOMERS]['add'] == TRUE) { ?>
                 <button id="add-customer" class="btn">
                     <i class="icon-plus"></i>
                     Add</button>
+                <?php } ?>
+                
+                <?php if ($privileges[PRIV_CUSTOMERS]['edit'] == TRUE) { ?>
                 <button id="edit-customer" class="btn" disabled="disabled">
                     <i class="icon-pencil"></i>
                     Edit</button>
+                <?php }?>
+                
+                <?php if ($privileges[PRIV_CUSTOMERS]['delete'] == TRUE) { ?>
                 <button id="delete-customer" class="btn" disabled="disabled">
                     <i class="icon-remove"></i>
                     Delete</button>
+                <?php } ?>
             </div>
             
             <div id="save-cancel-group" class="btn-group" style="display:none;">
diff --git a/src/application/views/backend/header.php b/src/application/views/backend/header.php
index 634f70bf..6d8ccf78 100644
--- a/src/application/views/backend/header.php
+++ b/src/application/views/backend/header.php
@@ -73,31 +73,37 @@
     <div id="header-menu">
         <?php // CALENDAR MENU ITEM 
               // ------------------------------------------------------ ?>
-        <a href="<?php echo $base_url; ?>backend" class="menu-item">
+        <?php $hidden = ($privileges[PRIV_APPOINTMENTS]['view'] == TRUE) ? '' : 'hidden'; ?>
+        <a href="<?php echo $base_url; ?>backend" class="menu-item <?php echo $hidden; ?>">
             Calendar
         </a>
         
         <?php // CUSTOMERS MENU ITEM 
               // ------------------------------------------------------ ?>
-        <a href="<?php echo $base_url; ?>backend/customers" class="menu-item">
+        <?php $hidden = ($privileges[PRIV_CUSTOMERS]['view'] == TRUE) ? '' : 'hidden'; ?>
+        <a href="<?php echo $base_url; ?>backend/customers" class="menu-item <?php echo $hidden; ?>">
             Customers
         </a>
         
         <?php // SERVICES MENU ITEM 
               // ------------------------------------------------------ ?>
-        <a href="<?php echo $base_url; ?>backend/services" class="menu-item">
+        <?php $hidden = ($privileges[PRIV_SERVICES]['view'] == TRUE) ? '' : 'hidden'; ?>
+        <a href="<?php echo $base_url; ?>backend/services" class="menu-item <?php echo $hidden; ?>">
             Services
         </a>
         
-        <?php // PROVIDERS MENU ITEM 
+        <?php // USERS MENU ITEM 
               // ------------------------------------------------------ ?>
-        <a href="<?php echo $base_url; ?>backend/users" class="menu-item">
+        <?php $hidden = ($privileges[PRIV_USERS]['view'] ==  TRUE) ? '' : 'hidden'; ?>
+        <a href="<?php echo $base_url; ?>backend/users" class="menu-item <?php echo $hidden; ?>">
             Users
         </a>
         
         <?php // SETTINGS MENU ITEM 
               // ------------------------------------------------------ ?>
-        <a href="<?php echo $base_url; ?>backend/settings" class="menu-item">
+        <?php $hidden = ($privileges[PRIV_SYSTEM_SETTINGS]['view'] == TRUE 
+                || $privileges[PRIV_USER_SETTINGS]['view'] == TRUE) ? '' : 'hidden'; ?>
+        <a href="<?php echo $base_url; ?>backend/settings" class="menu-item <?php echo $hidden; ?>">
             Settings
         </a>
         
diff --git a/src/application/views/backend/services.php b/src/application/views/backend/services.php
index 4ffdca6b..11111519 100644
--- a/src/application/views/backend/services.php
+++ b/src/application/views/backend/services.php
@@ -5,7 +5,13 @@
     var GlobalVariables = {
         'baseUrl': <?php echo '"' . $base_url . '"'; ?>,
         'services': <?php echo json_encode($services); ?>,
-        'categories': <?php echo json_encode($categories); ?>
+        'categories': <?php echo json_encode($categories); ?>,
+        'user'                  : {
+            'id'        : <?php echo $user_id; ?>,
+            'email'     : <?php echo '"' . $user_email . '"'; ?>,
+            'role_slug' : <?php echo '"' . $role_slug . '"'; ?>,
+            'privileges': <?php echo json_encode($privileges); ?>
+        }
     };
     
     $(document).ready(function() {
diff --git a/src/application/views/backend/settings.php b/src/application/views/backend/settings.php
index 761dc644..1003738b 100644
--- a/src/application/views/backend/settings.php
+++ b/src/application/views/backend/settings.php
@@ -14,6 +14,12 @@
         'settings': {
             'system': <?php echo json_encode($system_settings); ?>,
             'user': <?php echo json_encode($user_settings); ?>
+        },
+        'user'                  : {
+            'id'        : <?php echo $user_id; ?>,
+            'email'     : <?php echo '"' . $user_email . '"'; ?>,
+            'role_slug' : <?php echo '"' . $role_slug . '"'; ?>,
+            'privileges': <?php echo json_encode($privileges); ?>
         }
     };
     
@@ -24,9 +30,17 @@
 
 <div id="settings-page" class="row-fluid">
     <ul class="nav nav-tabs">
-        <li class="general-tab tab active"><a>General</a></li>
+        <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['view'] == TRUE) { ?>
+        <li class="general-tab tab"><a>General</a></li>
+        <?php } ?>
+        
+        <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['view'] == TRUE) { ?>
         <li class="business-logic-tab tab"><a>Business Logic</a></li>
+        <?php } ?>
+        
+        <?php if ($privileges[PRIV_USER_SETTINGS]['view'] == TRUE) { ?>
         <li class="user-tab tab"><a>User</a></li>
+        <?php } ?>
     </ul>
     
     <?php 
@@ -36,12 +50,15 @@
         // 
         // --------------------------------------------------------------
     ?>
-    <div id="general" class="tab-content">
+    <?php $hidden = ($privileges[PRIV_SYSTEM_SETTINGS]['view'] == TRUE) ? '' : 'hidden'; ?>
+    <div id="general" class="tab-content <?php echo $hidden; ?>">
         <form>
             <fieldset>
                 <legend>
                     General Settings
+                    <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE) { ?>
                     <button type="button" class="save-settings btn btn-primary btn-mini">Save</button>
+                    <?php } ?>
                 </legend>
                 
                 <label for="company-name">Company Name *</label>
@@ -80,12 +97,15 @@
         // 
         // --------------------------------------------------------------
     ?>
-    <div id="business-logic" class="tab-content" style="display: none;">
+    <?php $hidden = ($privileges[PRIV_SYSTEM_SETTINGS]['view'] == TRUE) ? '' : 'hidden'; ?>
+    <div id="business-logic" class="tab-content <?php echo $hidden; ?>">
         <form>
             <fieldset>
                 <legend>
                     Business Logic
+                    <?php if ($privileges[PRIV_SYSTEM_SETTINGS]['edit'] == TRUE) { ?>
                     <button type="button" class="save-settings btn btn-primary btn-mini">Save</button>
+                    <?php } ?>
                 </legend>
                 
                 <div class="row-fluid">
@@ -201,12 +221,15 @@
         // 
         // --------------------------------------------------------------
     ?>
-    <div id="user" class="tab-content" style="display: none;">
+    <?php $hidden = ($privileges[PRIV_USER_SETTINGS]['view'] == TRUE) ? '' : 'hidden'; ?>
+    <div id="user" class="tab-content <?php echo $hidden; ?>">
         <form class="row-fluid">
             <fieldset class="span5">
                 <legend>
                     Personal Info 
+                    <?php if ($privileges[PRIV_USER_SETTINGS]['edit'] == TRUE) { ?>
                     <button type="button" class="save-settings btn btn-primary btn-mini">Save</button>
+                    <?php } ?>
                 </legend>
                 
                 <input type="hidden" id="user-id" />
diff --git a/src/application/views/backend/users.php b/src/application/views/backend/users.php
index 07877efe..9d57be40 100644
--- a/src/application/views/backend/users.php
+++ b/src/application/views/backend/users.php
@@ -23,7 +23,13 @@
         'providers': <?php echo json_encode($providers); ?>,
         'secretaries': <?php echo json_encode($secretaries); ?>,
         'services': <?php echo json_encode($services); ?>,
-        'workingPlan': $.parseJSON(<?php echo json_encode($working_plan); ?>)
+        'workingPlan': $.parseJSON(<?php echo json_encode($working_plan); ?>),
+        'user'                  : {
+            'id'        : <?php echo $user_id; ?>,
+            'email'     : <?php echo '"' . $user_email . '"'; ?>,
+            'role_slug' : <?php echo '"' . $role_slug . '"'; ?>,
+            'privileges': <?php echo json_encode($privileges); ?>
+        }
     };
     
     $(document).ready(function() {
diff --git a/src/application/views/user/no_privileges.php b/src/application/views/user/no_privileges.php
index b6eddc13..73a0f403 100644
--- a/src/application/views/user/no_privileges.php
+++ b/src/application/views/user/no_privileges.php
@@ -1,7 +1,73 @@
-<?php
-
-/*
- * To change this template, choose Tools | Templates
- * and open the template in the editor.
- */
-?>
+<!DOCTYPE html>
+<html>
+<head>
+    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
+    
+    <?php // INCLUDE JS FILES ?>
+    <script 
+        type="text/javascript" 
+        src="<?php echo $this->config->base_url(); ?>assets/js/libs/jquery/jquery.min.js"></script>
+    <script 
+        type="text/javascript" 
+        src="<?php echo $this->config->base_url(); ?>assets/js/libs/bootstrap/bootstrap.min.js"></script>   
+        
+    <?php // INCLUDE CSS FILES ?>
+    <link 
+        rel="stylesheet" 
+        type="text/css" 
+        href="<?php echo $this->config->base_url(); ?>assets/css/libs/bootstrap/bootstrap.css">
+    <link 
+        rel="stylesheet" 
+        type="text/css" 
+        href="<?php echo $this->config->base_url(); ?>assets/css/libs/bootstrap/bootstrap-responsive.css">
+    
+    <?php // SET FAVICON FOR PAGE ?>
+    <link 
+        rel="icon" 
+        type="image/x-icon" 
+        href="<?php echo $this->config->base_url(); ?>assets/images/favicon.ico">
+    
+    <style>
+        body {
+            background-color: #CAEDF3;
+        }
+        
+        #no-priv-frame {
+            width: 630px;
+            margin: 150px auto 0 auto;
+            background: #FFF;
+            border: 1px solid #DDDADA;
+            padding: 70px;
+        }
+        
+        #login-icon {
+            float: right;
+            margin-top: 17px;
+        }
+        
+        label {
+            font-weight: bold;
+        }
+        
+        .btn {
+            margin-right: 10px;
+        }
+    </style>
+</head>
+<body>
+    <div id="no-priv-frame" class="frame-container">
+        <h3>No Privileges</h3>
+        <p>
+            You do not have the required privileges to view this page. Please navigate to a 
+            different section.
+        </p>  
+        
+        <br>
+        
+        <a href="<?php echo $this->config->base_url(); ?>backend" class="btn btn-danger btn-large">
+            <i class="icon-wrench icon-white"></i>
+            Backend Calendar
+        </a>
+    </div>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/assets/css/backend.css b/src/assets/css/backend.css
index 0bf3dea5..12dd5348 100644
--- a/src/assets/css/backend.css
+++ b/src/assets/css/backend.css
@@ -90,7 +90,7 @@ root {
 }
 
 #modal-message { 
-    margin: 10px 0px; 
+    margin: 10px; 
 }
 
 body .modal-header {
@@ -160,7 +160,7 @@ body .modal-header h3 {
 }
 
 #calendar .fc-header-title h2 {
-    font-size: 20px;
+    font-size: 18px;
     margin: 0px;
     line-height: 32px;
 }
@@ -192,6 +192,34 @@ body .modal-header h3 {
     margin-left: -430px;
 }
 
+#existing-customers-list { 
+    height: 110px;
+    overflow-y: auto;
+    margin-bottom: 8px;
+    font-size: 12px;
+    line-height: 22px;
+}
+
+#existing-customers-list div {
+    display: inline-block;
+    width: 250px;
+    margin: 0 5px 5px 0;
+    padding: 3px 5px;
+    border-radius: 3px;
+}
+
+#existing-customers-list div:hover {
+    background: #B8F0C1;
+    font-weight: bold;
+    cursor: pointer;
+}
+
+#filter-existing-customers {
+    display: inline-block;
+    height: 14px;
+    font-size: 12px;
+}
+
 /* BACKEND CUSTOMERS PAGE
    -------------------------------------------------------------------- */
 #customers-page #filter-customers {
diff --git a/src/assets/js/backend.js b/src/assets/js/backend.js
index 561b26ab..aab93a17 100644
--- a/src/assets/js/backend.js
+++ b/src/assets/js/backend.js
@@ -30,6 +30,11 @@ var Backend = {
     DB_SLUG_SECRETARY: 'secretary',
     DB_SLUG_CUSTOMER: 'customer',
     
+    PRIV_VIEW: 1,
+    PRIV_ADD: 2,
+    PRIV_EDIT: 4,
+    PRIV_DELETE: 8,
+    
     /**
      * Place the backend footer always on the bottom of the page.
      */
@@ -62,12 +67,15 @@ var Backend = {
      * 'function' key values.
      */
     displayNotification: function(message, actions) {
-        if (message === undefined) {
+        if (message == undefined) {
             message = 'NO MESSAGE PROVIDED FOR THIS NOTIFICATION';
         }
         
-        if (actions === undefined) {
+        if (actions == undefined) {
             actions = [];
+            setTimeout(function() {
+                $('#notification').slideUp('slow');
+            }, 7000);
         }
         
         var notificationHtml = 
diff --git a/src/assets/js/backend_calendar.js b/src/assets/js/backend_calendar.js
index 781b2928..c18fa6a0 100644
--- a/src/assets/js/backend_calendar.js
+++ b/src/assets/js/backend_calendar.js
@@ -671,6 +671,98 @@ var BackendCalendar = {
             $dialog.find('.modal-header h3').text('New Unavailable Period');
             $dialog.modal('show');
         });
+        
+        /**
+         * Event: Pick Existing Customer Button "Click"
+         */
+        $('#select-customer').click(function() {
+            var $list = $('#existing-customers-list');
+            
+            if (!$list.is(':visible')) {
+                $(this).text('Hide List');
+                $list.empty();
+                $list.slideDown('slow');
+                $('#filter-existing-customers').fadeIn('slow');
+                $('#filter-existing-customers').val('');
+                $.each(GlobalVariables.customers, function(index, c) {
+                    $list.append('<div data-id="' + c.id + '">' 
+                            + c.first_name + ' ' + c.last_name + '</div>');
+                });
+            } else {
+                $list.slideUp('slow');
+                $('#filter-existing-customers').fadeOut('slow');
+                $(this).text('Select Existing Customer');
+            }
+        });
+        
+        /**
+         * Event: Select Existing Customer From List "Click"
+         */
+        $(document).on('click', '#existing-customers-list div', function() {
+            var id = $(this).attr('data-id');
+            
+            $.each(GlobalVariables.customers, function(index, c) {
+                if (c.id == id) {
+                    $('#customer-id').val(c.id);
+                    $('#first-name').val(c.first_name);
+                    $('#last-name').val(c.last_name);
+                    $('#email').val(c.email);
+                    $('#phone-number').val(c.phone_number);
+                    $('#address').val(c.address);
+                    $('#city').val(c.city);
+                    $('#zip-code').val(c.zip_code);
+                    return false;
+                }
+            });
+            
+            $('#select-customer').trigger('click'); // hide list
+        });
+        
+        /**
+         * Event: Filter Existing Customers "Change"
+         */
+        $('#filter-existing-customers').keyup(function() {
+            var key = $(this).val();
+            var $list = $('#existing-customers-list');
+            $list.empty();
+            $.each(GlobalVariables.customers, function(index, c) {
+                if (c.first_name.indexOf(key) != -1 
+                        || c.last_name.indexOf(key) != -1
+                        || c.email.indexOf(key) != -1
+                        || c.phone_number.indexOf(key) != -1
+                        || c.address.indexOf(key) != -1
+                        || c.city.indexOf(key) != -1
+                        || c.zip_code.indexOf(key) != -1) {
+                    $list.append('<div data-id="' + c.id + '">' 
+                            + c.first_name + ' ' + c.last_name + '</div>');
+                }
+            });
+        });
+        
+        /**
+         * Event: Selected Service "Change"
+         * 
+         * When the user clicks on a service, its available providers should 
+         * become visible. 
+         */
+        $('#select-service').change(function() {
+            var sid = $('#select-service').val();
+            $('#select-provider').empty();
+
+            $.each(GlobalVariables.availableProviders, function(indexProvider, provider) {
+                $.each(provider.services, function(indexService, serviceId) {
+                    // If the current provider is able to provide the selected service,
+                    // add him to the listbox. 
+                    if (serviceId == sid) { 
+                        var optionHtml = '<option value="' + provider['id'] + '">' 
+                                + provider['last_name']  + ' ' + provider['first_name'] 
+                                + '</option>';
+                        $('#select-provider').append(optionHtml);
+                    }
+                });
+            });
+        });
+        
     },
             
     /**
@@ -1011,6 +1103,13 @@ var BackendCalendar = {
      */
     calendarEventResize: function(event, dayDelta, minuteDelta, revertFunc, 
             jsEvent, ui, view) {
+        if (GlobalVariables.user.privileges.appointments.edit == false) {
+            revertFunc();
+            Backend.displayNotification('You do not have the required privileges to '
+                    + 'edit appointments.');
+            return;
+        }
+                
         if ($('#notification').is(':visible')) {
             $('#notification').hide('bind');
         }  
@@ -1164,7 +1263,7 @@ var BackendCalendar = {
     calendarEventClick: function(event, jsEvent, view) {
         $('.popover').remove(); // Close all open popovers.
         
-        var html; // Popover's html code
+        var html, displayEdit, displayDelete; 
         
         // Depending where the user clicked the event (title or empty space) we 
         // need to use different selectors to reach the parent element.
@@ -1172,9 +1271,11 @@ var BackendCalendar = {
         var $altParent = $(jsEvent.target).parents().eq(1);
         
         if ($parent.hasClass('fc-unavailable') || $altParent.hasClass('fc-unavailable')) {
-            var displayEdit = ($parent.hasClass('fc-custom') || $altParent.hasClass('fc-custom')) 
+            displayEdit = (($parent.hasClass('fc-custom') || $altParent.hasClass('fc-custom'))
+                    && GlobalVariables.user.privileges.appointments.edit == true) 
                     ? '' : 'hide';
-            var displayDelete = displayEdit; // Same value at the time.
+            displayDelete = (GlobalVariables.user.privileges.appointments.delete == true) 
+                    ? '' : 'hide'; // Same value at the time.
             
             var notes = ''; 
             if (event.data) { // Only custom unavailable periods have notes.
@@ -1199,7 +1300,12 @@ var BackendCalendar = {
                         '<button class="delete-popover btn btn-danger ' + displayDelete + '">Delete</button>' +
                         '<button class="close-popover btn" data-po=' + jsEvent.target + '>Close</button>' +
                     '</center>';
-        } else {        
+        } else {   
+            displayEdit = (GlobalVariables.user.privileges.appointments.edit == true) 
+                    ? '' : 'hide'; 
+            displayDelete = (GlobalVariables.user.privileges.appointments.delete == true) 
+                    ? '' : 'hide'; 
+            
             html = 
                     '<style type="text/css">' 
                         + '.popover-content strong {min-width: 80px; display:inline-block;}' 
@@ -1223,8 +1329,8 @@ var BackendCalendar = {
                         + event.data['customer']['last_name'] 
                         + '<hr>' +
                     '<center>' + 
-                        '<button class="edit-popover btn btn-primary">Edit</button>' +
-                        '<button class="delete-popover btn btn-danger">Delete</button>' +
+                        '<button class="edit-popover btn btn-primary ' + displayEdit + '">Edit</button>' +
+                        '<button class="delete-popover btn btn-danger ' + displayDelete + '">Delete</button>' +
                         '<button class="close-popover btn" data-po=' + jsEvent.target + '>Close</button>' +
                     '</center>';
         }
@@ -1254,6 +1360,13 @@ var BackendCalendar = {
      */
     calendarEventDrop : function(event, dayDelta, minuteDelta, allDay, 
             revertFunc, jsEvent, ui, view) {
+        if (GlobalVariables.user.privileges.appointments.edit == false) {
+            revertFunc();
+            Backend.displayNotification('You do not have the required privileges to '
+                    + 'edit appointments.');
+            return;
+        }
+                
         if ($('#notification').is(':visible')) {
             $('#notification').hide('bind');
         }    
@@ -1458,7 +1571,7 @@ var BackendCalendar = {
         
         // :: EMPTY FORM FIELDS
         $dialog.find('input, textarea').val('');
-        $dialog.find('#modal-message').hide();
+        $dialog.find('.modal-message').hide();
         $dialog.find('#select-service, #select-provider').empty();
         
         // :: PREPARE SERVICE AND PROVIDER LISTBOXES
@@ -1526,7 +1639,7 @@ var BackendCalendar = {
         
         // Reset previous validation css formating.
         $dialog.find('.control-group').removeClass('error');
-        $dialog.find('#modal-message').hide();
+        $dialog.find('.modal-message').hide();
         
         try {
             // :: CHECK REQUIRED FIELDS
@@ -1549,7 +1662,7 @@ var BackendCalendar = {
             
             return true;
         } catch(exc) {
-            $dialog.find('#modal-message').addClass('alert-error').text(exc).show('fade');
+            $dialog.find('.modal-message').addClass('alert-error').text(exc).show('fade');
             return false;
         }
     },
diff --git a/src/assets/js/backend_customers.js b/src/assets/js/backend_customers.js
index 710b8761..7470d7d3 100644
--- a/src/assets/js/backend_customers.js
+++ b/src/assets/js/backend_customers.js
@@ -294,12 +294,17 @@ CustomersHelper.prototype.validate = function(customer) {
  */
 CustomersHelper.prototype.resetForm = function() {
     $('#details').find('input, textarea').val(''); 
+    $('#details').find('input, textarea').prop('readonly', true); 
+    
     $('#customer-appointments').html('');
     $('#appointment-details').html('');
     $('#edit-customer, #delete-customer').prop('disabled', true);
     $('#add-edit-delete-group').show();
     $('#save-cancel-group').hide();
     
+    $('#details .required').css('border', '');
+    $('#details #form-message').hide();
+    
     $('#filter-customers button').prop('disabled', false);
     $('#filter-customers .selected-row').removeClass('selected-row');
     $('#filter-customers .results').css('color', '');
diff --git a/src/assets/js/backend_services.js b/src/assets/js/backend_services.js
index 2a19397a..7eca44af 100644
--- a/src/assets/js/backend_services.js
+++ b/src/assets/js/backend_services.js
@@ -292,7 +292,7 @@ ServicesHelper.prototype.delete = function(id) {
         
         BackendServices.helper.resetForm();
         BackendServices.helper.filter($('#filter-services .key').val());
-    });
+    }, 'json');
 };
 
 /**
@@ -641,7 +641,7 @@ CategoriesHelper.prototype.save = function(category) {
         $('#filter-categories .key').val('');
         BackendServices.helper.filter('', response.id, true);
         BackendServices.updateAvailableCategories();
-    });
+    }, 'json');
 };
 
 /**
@@ -665,7 +665,7 @@ CategoriesHelper.prototype.delete = function(id) {
         BackendServices.helper.resetForm();
         BackendServices.helper.filter($('#filter-categories .key').val());
         BackendServices.updateAvailableCategories();
-    });
+    }, 'json');
 };
 
 /**
diff --git a/src/assets/js/backend_settings.js b/src/assets/js/backend_settings.js
index 17f6c130..422dfee3 100644
--- a/src/assets/js/backend_settings.js
+++ b/src/assets/js/backend_settings.js
@@ -81,7 +81,21 @@ var BackendSettings = {
         
         if (bindEventHandlers) {
             BackendSettings.bindEventHandlers();
+            $('#settings-page .nav li').first().addClass('active');
+            $('#settings-page .nav li').first().find('a').trigger('click');
         }
+        
+        // Apply Privileges
+        if (GlobalVariables.user.privileges.system_settings.edit == false) {
+            $('#general, #business-logic').find('select, input, textarea').prop('readonly', true);
+            $('#general, #business-logic').find('button').prop('disabled', true);
+        }
+        
+        if (GlobalVariables.user.privileges.user_settings.edit == false) {
+            $('#user').find('select, input, textarea').prop('readonly', true);
+            $('#user').find('button').prop('disabled', true);
+        }
+        
     },
             
     /**
diff --git a/src/assets/js/backend_users_admins.js b/src/assets/js/backend_users_admins.js
index de974c54..2697f647 100644
--- a/src/assets/js/backend_users_admins.js
+++ b/src/assets/js/backend_users_admins.js
@@ -201,7 +201,7 @@ AdminsHelper.prototype.delete = function(id) {
         Backend.displayNotification('Admin deleted successfully!');
         BackendUsers.helper.resetForm();
         BackendUsers.helper.filter($('#filter-admins .key').val());
-    });
+    }, 'json');
 };
 
 /**
diff --git a/src/assets/js/backend_users_providers.js b/src/assets/js/backend_users_providers.js
index be0ec2ee..331c1feb 100644
--- a/src/assets/js/backend_users_providers.js
+++ b/src/assets/js/backend_users_providers.js
@@ -242,7 +242,7 @@ ProvidersHelper.prototype.delete = function(id) {
         Backend.displayNotification('Provider deleted successfully!');
         BackendUsers.helper.resetForm();
         BackendUsers.helper.filter($('#filter-providers .key').val());
-    });
+    }, 'json');
 };
 
 /**
diff --git a/src/assets/js/backend_users_secretaries.js b/src/assets/js/backend_users_secretaries.js
index bc0369b8..c742b42e 100644
--- a/src/assets/js/backend_users_secretaries.js
+++ b/src/assets/js/backend_users_secretaries.js
@@ -212,7 +212,7 @@ SecretariesHelper.prototype.delete = function(id) {
         Backend.displayNotification('Secretary deleted successfully!');
         BackendUsers.helper.resetForm();
         BackendUsers.helper.filter($('#filter-secretaries .key').val());
-    });
+    }, 'json');
 };
 
 /**