diff --git a/application/controllers/Services.php b/application/controllers/Services.php
index f18636f9..b02f7248 100644
--- a/application/controllers/Services.php
+++ b/application/controllers/Services.php
@@ -36,7 +36,7 @@ class Services extends EA_Controller {
     /**
      * Render the backend services page.
      *
-     * On this page admin users will be able to manage services, which are eventually selected by customers during the 
+     * On this page admin users will be able to manage services, which are eventually selected by customers during the
      * booking process.
      */
     public function index()
@@ -51,7 +51,12 @@ class Services extends EA_Controller {
         $user_id = session('user_id');
 
         $role_slug = session('role_slug');
-        
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+        ]);
+
         html_vars([
             'page_title' => lang('services'),
             'active_menu' => PRIV_SERVICES,
@@ -80,7 +85,7 @@ class Services extends EA_Controller {
             $order_by = 'name ASC';
 
             $limit = request('limit', 1000);
-            
+
             $offset = 0;
 
             $services = $this->services_model->search($keyword, $limit, $offset, $order_by);
@@ -100,7 +105,9 @@ class Services extends EA_Controller {
     {
         try
         {
-            $service = json_decode(request('service'), TRUE);
+            $service = request('service');
+
+            $service['id_categories'] = $service['id_categories'] ?: null;
 
             if (cannot('add', PRIV_SERVICES))
             {
@@ -127,13 +134,15 @@ class Services extends EA_Controller {
     {
         try
         {
-            $service = json_decode(request('service'), TRUE);
+            $service = request('service');
+            
+            $service['id_categories'] = $service['id_categories'] ?: null; 
 
             if (cannot('edit', PRIV_SERVICES))
             {
                 abort(403, 'Forbidden');
             }
-
+            
             $service_id = $this->services_model->save($service);
 
             json_response([
diff --git a/application/views/pages/services.php b/application/views/pages/services.php
index 409f662a..796cb491 100755
--- a/application/views/pages/services.php
+++ b/application/views/pages/services.php
@@ -146,27 +146,11 @@
 
 <?php section('scripts') ?>
 
-<script src="<?= asset_url('assets/js/pages/backend_services_helper.js') ?>"></script>
-<script src="<?= asset_url('assets/js/pages/backend_services.js') ?>"></script>
-<script>
-    var GlobalVariables = {
-        csrfToken: <?= json_encode($this->security->get_csrf_hash()) ?>,
-        baseUrl: <?= json_encode(config('base_url')) ?>,
-        dateFormat: <?= json_encode(setting('date_format')) ?>,
-        timeFormat: <?= json_encode(setting('time_format')) ?>,
-        timezones: <?= json_encode($timezones) ?>,
-        user: {
-            id: <?= session('user_id') ?>,
-            email: <?= json_encode(session('user_email')) ?>,
-            timezone: <?= json_encode(session('timezone')) ?>,
-            role_slug: <?= json_encode(session('role_slug')) ?>,
-            privileges: <?= json_encode($privileges) ?>
-        }
-    };
-
-    $(function () {
-        BackendServices.initialize(true);
-    });
-</script>
+<script src="<?= asset_url('assets/js/utils/message.js') ?>"></script>
+<script src="<?= asset_url('assets/js/utils/validation.js') ?>"></script>
+<script src="<?= asset_url('assets/js/utils/url.js') ?>"></script>
+<script src="<?= asset_url('assets/js/http/services_http_client.js') ?>"></script>
+<script src="<?= asset_url('assets/js/http/categories_http_client.js') ?>"></script>
+<script src="<?= asset_url('assets/js/pages/services.js') ?>"></script>
 
 <?php section('scripts') ?>
diff --git a/assets/js/http/services_http_client.js b/assets/js/http/services_http_client.js
index edc118b0..e44c2452 100644
--- a/assets/js/http/services_http_client.js
+++ b/assets/js/http/services_http_client.js
@@ -10,6 +10,17 @@
  * ---------------------------------------------------------------------------- */
 
 App.Http.Services = (function () {
+    /**
+     * Save (create or update) a service.
+     *
+     * @param {Object} service
+     *
+     * @return {Object}
+     */
+    function save(service) {
+        return service.id ? update(service) : create(service);
+    }
+
     /**
      * Create an service.
      *
@@ -107,6 +118,7 @@ App.Http.Services = (function () {
     }
 
     return {
+        save,
         create,
         update,
         destroy,
diff --git a/assets/js/pages/backend_services.js b/assets/js/pages/backend_services.js
deleted file mode 100644
index 89d9d415..00000000
--- a/assets/js/pages/backend_services.js
+++ /dev/null
@@ -1,91 +0,0 @@
-/* ----------------------------------------------------------------------------
- * Easy!Appointments - Open Source Web Scheduler
- *
- * @package     EasyAppointments
- * @author      A.Tselegidis <alextselegidis@gmail.com>
- * @copyright   Copyright (c) Alex Tselegidis
- * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
- * @link        https://easyappointments.org
- * @since       v1.0.0
- * ---------------------------------------------------------------------------- */
-
-window.BackendServices = window.BackendServices || {};
-
-/**
- * Backend Services
- *
- * This namespace handles the js functionality of the backend services page.
- *
- * @module BackendServices
- */
-(function (exports) {
-    'use strict';
-
-    /**
-     * Contains the basic record methods for the page.
-     *
-     * @type {ServicesHelper}
-     */
-    var helper;
-
-    var servicesHelper = new ServicesHelper();
-
-    /**
-     * Default initialize method of the page.
-     *
-     * @param {Boolean} [defaultEventHandlers] Optional (true), determines whether to bind the  default event handlers.
-     */
-    exports.initialize = function (defaultEventHandlers) {
-        defaultEventHandlers = defaultEventHandlers || true;
-
-        // Instantiate helper object (service helper by default).
-        helper = servicesHelper;
-        helper.resetForm();
-        helper.filter('');
-        helper.bindEventHandlers();
-
-        if (defaultEventHandlers) {
-            bindEventHandlers();
-        }
-
-        BackendServices.updateAvailableCategories();
-
-        Backend.placeFooterToBottom();
-    };
-
-    /**
-     * Binds the default event handlers of the backend services page.
-     *
-     * Do not use this method if you include the "BackendServices" namespace on another page.
-     */
-    function bindEventHandlers() {
-        //
-    }
-
-    /**
-     * Update the service category list box.
-     *
-     * Use this method every time a change is made to the service categories db table.
-     */
-    exports.updateAvailableCategories = function () {
-        var url = GlobalVariables.baseUrl + '/index.php/categories/search';
-
-        var data = {
-            csrf_token: GlobalVariables.csrfToken,
-            key: ''
-        };
-
-        $.post(url, data).done(function (response) {
-            GlobalVariables.categories = response;
-            var $select = $('#service-category');
-
-            $select.empty();
-
-            response.forEach(function (category) {
-                $select.append(new Option(category.name, category.id));
-            });
-
-            $select.append(new Option('- ' + App.Lang.no_category + ' -', null)).val('null');
-        });
-    };
-})(window.BackendServices);
diff --git a/assets/js/pages/backend_services_helper.js b/assets/js/pages/services.js
similarity index 57%
rename from assets/js/pages/backend_services_helper.js
rename to assets/js/pages/services.js
index dd5f046a..c8a7a4ef 100644
--- a/assets/js/pages/backend_services_helper.js
+++ b/assets/js/pages/services.js
@@ -9,35 +9,23 @@
  * @since       v1.0.0
  * ---------------------------------------------------------------------------- */
 
-(function () {
-    'use strict';
-
-    /**
-     * ServicesHelper
-     *
-     * This class contains the methods that will be used by the "Services" tab of the page.
-     *
-     * @class ServicesHelper
-     */
-    function ServicesHelper() {
-        this.filterResults = {};
-        this.filterLimit = 20;
-    }
-
-    ServicesHelper.prototype.bindEventHandlers = function () {
-        var instance = this;
+App.Pages.Services = (function () {
+    const $services = $('#services');
+    let filterResults = {};
+    let filterLimit = 20;
 
+    function bindEventHandlers() {
         /**
          * Event: Filter Services Form "Submit"
          *
          * @param {jQuery.Event} event
          */
-        $('#services').on('submit', '#filter-services form', function (event) {
+        $services.on('submit', '#filter-services form', function (event) {
             event.preventDefault();
-            var key = $('#filter-services .key').val();
+            const key = $('#filter-services .key').val();
             $('#filter-services .selected').removeClass('selected');
-            instance.resetForm();
-            instance.filter(key);
+            resetForm();
+            filter(key);
         });
 
         /**
@@ -45,21 +33,22 @@
          *
          * Display the selected service data to the user.
          */
-        $('#services').on('click', '.service-row', function () {
+        $services.on('click', '.service-row', function () {
             if ($('#filter-services .filter').prop('disabled')) {
                 $('#filter-services .results').css('color', '#AAA');
                 return; // exit because we are on edit mode
             }
 
-            var serviceId = $(this).attr('data-id');
+            const serviceId = $(this).attr('data-id');
 
-            var service = instance.filterResults.find(function (filterResult) {
+            const service = filterResults.find(function (filterResult) {
                 return Number(filterResult.id) === Number(serviceId);
             });
 
             // Add dedicated provider link.
-            var dedicatedUrl = GlobalVariables.baseUrl + '/index.php?service=' + encodeURIComponent(service.id);
-            var $link = $('<a/>', {
+            const dedicatedUrl = App.Utils.Url.siteUrl('?service=' + encodeURIComponent(service.id));
+
+            const $link = $('<a/>', {
                 'href': dedicatedUrl,
                 'html': [
                     $('<span/>', {
@@ -70,7 +59,7 @@
 
             $('#services .record-details h3').find('a').remove().end().append($link);
 
-            instance.display(service);
+            display(service);
             $('#filter-services .selected').removeClass('selected');
             $(this).addClass('selected');
             $('#edit-service, #delete-service').prop('disabled', false);
@@ -79,8 +68,8 @@
         /**
          * Event: Add New Service Button "Click"
          */
-        $('#services').on('click', '#add-service', function () {
-            instance.resetForm();
+        $services.on('click', '#add-service', function () {
+            resetForm();
             $('#services .add-edit-delete-group').hide();
             $('#services .save-cancel-group').show();
             $('#services .record-details').find('input, select, textarea').prop('disabled', false);
@@ -92,7 +81,7 @@
             $('#service-duration').val('30');
             $('#service-price').val('0');
             $('#service-currency').val('');
-            $('#service-category').val('null');
+            $('#service-category').val('');
             $('#service-availabilities-type').val('flexible');
             $('#service-attendants-number').val('1');
         });
@@ -102,19 +91,19 @@
          *
          * Cancel add or edit of a service record.
          */
-        $('#services').on('click', '#cancel-service', function () {
-            var id = $('#service-id').val();
-            instance.resetForm();
+        $services.on('click', '#cancel-service', function () {
+            const id = $('#service-id').val();
+            resetForm();
             if (id !== '') {
-                instance.select(id, true);
+                select(id, true);
             }
         });
 
         /**
          * Event: Save Service Button "Click"
          */
-        $('#services').on('click', '#save-service', function () {
-            var service = {
+        $services.on('click', '#save-service', function () {
+            const service = {
                 name: $('#service-name').val(),
                 duration: $('#service-duration').val(),
                 price: $('#service-price').val(),
@@ -122,30 +111,25 @@
                 description: $('#service-description').val(),
                 location: $('#service-location').val(),
                 availabilities_type: $('#service-availabilities-type').val(),
-                attendants_number: $('#service-attendants-number').val()
+                attendants_number: $('#service-attendants-number').val(),
+                id_categories: $('#service-category').val() || null
             };
 
-            if ($('#service-category').val() !== 'null') {
-                service.id_categories = $('#service-category').val();
-            } else {
-                service.id_categories = null;
-            }
-
             if ($('#service-id').val() !== '') {
                 service.id = $('#service-id').val();
             }
 
-            if (!instance.validate()) {
+            if (!validate()) {
                 return;
             }
 
-            instance.save(service);
+            save(service);
         });
 
         /**
          * Event: Edit Service Button "Click"
          */
-        $('#services').on('click', '#edit-service', function () {
+        $services.on('click', '#edit-service', function () {
             $('#services .add-edit-delete-group').hide();
             $('#services .save-cancel-group').show();
             $('#services .record-details').find('input, select, textarea').prop('disabled', false);
@@ -156,9 +140,9 @@
         /**
          * Event: Delete Service Button "Click"
          */
-        $('#services').on('click', '#delete-service', function () {
-            var serviceId = $('#service-id').val();
-            var buttons = [
+        $services.on('click', '#delete-service', function () {
+            const serviceId = $('#service-id').val();
+            const buttons = [
                 {
                     text: App.Lang.cancel,
                     click: function () {
@@ -168,30 +152,15 @@
                 {
                     text: App.Lang.delete,
                     click: function () {
-                        instance.delete(serviceId);
+                        remove(serviceId);
                         $('#message-box').dialog('close');
                     }
                 }
             ];
 
-            GeneralFunctions.displayMessageBox(App.Lang.delete_service, App.Lang.delete_record_prompt, buttons);
+            App.Utils.Message.show(App.Lang.delete_service, App.Lang.delete_record_prompt, buttons);
         });
-    };
-
-    /**
-     * Remove the previously registered event handlers.
-     */
-    ServicesHelper.prototype.unbindEventHandlers = function () {
-        $('#services')
-            .off('submit', '#filter-services form')
-            .off('click', '#filter-services .clear')
-            .off('click', '.service-row')
-            .off('click', '#add-service')
-            .off('click', '#cancel-service')
-            .off('click', '#save-service')
-            .off('click', '#edit-service')
-            .off('click', '#delete-service');
-    };
+    }
 
     /**
      * Save service record to database.
@@ -199,59 +168,40 @@
      * @param {Object} service Contains the service record data. If an 'id' value is provided
      * then the update operation is going to be executed.
      */
-    ServicesHelper.prototype.save = function (service) {
-        var url = GlobalVariables.baseUrl + '/index.php/services/' + (service.id ? 'update' : 'create');
-
-        var data = {
-            csrf_token: GlobalVariables.csrfToken,
-            service: JSON.stringify(service)
-        };
-
-        $.post(url, data).done(
-            function (response) {
-                Backend.displayNotification(App.Lang.service_saved);
-                this.resetForm();
-                $('#filter-services .key').val('');
-                this.filter('', response.id, true);
-            }.bind(this)
-        );
-    };
+    function save(service) {
+        App.Http.Services.save(service).then((response) => {
+            Backend.displayNotification(App.Lang.service_saved);
+            resetForm();
+            $('#filter-services .key').val('');
+            filter('', response.id, true);
+        });
+    }
 
     /**
      * Delete a service record from database.
      *
      * @param {Number} id Record ID to be deleted.
      */
-    ServicesHelper.prototype.delete = function (id) {
-        var url = GlobalVariables.baseUrl + '/index.php/services/destroy';
-
-        var data = {
-            csrf_token: GlobalVariables.csrfToken,
-            service_id: id
-        };
-
-        $.post(url, data).done(
-            function () {
-                Backend.displayNotification(App.Lang.service_deleted);
-
-                this.resetForm();
-                this.filter($('#filter-services .key').val());
-            }.bind(this)
-        );
-    };
+    function remove(id) {
+        App.Http.Services.destroy(id).then(() => {
+            Backend.displayNotification(App.Lang.service_deleted);
+            resetForm();
+            filter($('#filter-services .key').val());
+        });
+    }
 
     /**
      * Validates a service record.
      *
      * @return {Boolean} Returns the validation result.
      */
-    ServicesHelper.prototype.validate = function () {
+    function validate() {
         $('#services .is-invalid').removeClass('is-invalid');
         $('#services .form-message').removeClass('alert-danger').hide();
 
         try {
             // Validate required fields.
-            var missingRequired = false;
+            let missingRequired = false;
 
             $('#services .required').each(function (index, requiredField) {
                 if (!$(requiredField).val()) {
@@ -275,12 +225,12 @@
             $('#services .form-message').addClass('alert-danger').text(error.message).show();
             return false;
         }
-    };
+    }
 
     /**
      * Resets the service tab form back to its initial state.
      */
-    ServicesHelper.prototype.resetForm = function () {
+    function resetForm() {
         $('#filter-services .selected').removeClass('selected');
         $('#filter-services button').prop('disabled', false);
         $('#filter-services .results').css('color', '');
@@ -294,14 +244,14 @@
 
         $('#services .record-details .is-invalid').removeClass('is-invalid');
         $('#services .record-details .form-message').hide();
-    };
+    }
 
     /**
      * Display a service record into the service form.
      *
      * @param {Object} service Contains the service record data.
      */
-    ServicesHelper.prototype.display = function (service) {
+    function display(service) {
         $('#service-id').val(service.id);
         $('#service-name').val(service.name);
         $('#service-duration').val(service.duration);
@@ -312,9 +262,9 @@
         $('#service-availabilities-type').val(service.availabilities_type);
         $('#service-attendants-number').val(service.attendants_number);
 
-        var categoryId = service.id_categories !== null ? service.id_categories : 'null';
+        const categoryId = service.id_categories !== null ? service.id_categories : '';
         $('#service-category').val(categoryId);
-    };
+    }
 
     /**
      * Filters service records depending a string keyword.
@@ -322,55 +272,41 @@
      * @param {String} keyword This is used to filter the service records of the database.
      * @param {Number} selectId Optional, if set then after the filter operation the record with this
      * ID will be selected (but not displayed).
-     * @param {Boolean} display Optional (false), if true then the selected record will be displayed on the form.
+     * @param {Boolean} show Optional (false), if true then the selected record will be displayed on the form.
      */
-    ServicesHelper.prototype.filter = function (keyword, selectId, display) {
-        display = display || false;
+    function filter(keyword, selectId = null, show = false) {
+        App.Http.Services.search(keyword, filterLimit).then((response) => {
+            filterResults = response;
 
-        var url = GlobalVariables.baseUrl + '/index.php/services/search';
+            $('#filter-services .results').empty();
 
-        var data = {
-            csrf_token: GlobalVariables.csrfToken,
-            keyword: keyword,
-            limit: this.filterLimit
-        };
+            response.forEach(function (service, index) {
+                $('#filter-services .results').append(getFilterHtml(service)).append($('<hr/>'));
+            });
 
-        $.post(url, data).done(
-            function (response) {
-                this.filterResults = response;
+            if (response.length === 0) {
+                $('#filter-services .results').append(
+                    $('<em/>', {
+                        'text': App.Lang.no_records_found
+                    })
+                );
+            } else if (response.length === filterLimit) {
+                $('<button/>', {
+                    'type': 'button',
+                    'class': 'btn btn-outline-secondary w-100 load-more text-center',
+                    'text': App.Lang.load_more,
+                    'click': function () {
+                        filterLimit += 20;
+                        filter(keyword, selectId, show);
+                    }.bind(this)
+                }).appendTo('#filter-services .results');
+            }
 
-                $('#filter-services .results').empty();
-
-                response.forEach(function (service, index) {
-                    $('#filter-services .results')
-                        .append(ServicesHelper.prototype.getFilterHtml(service))
-                        .append($('<hr/>'));
-                });
-
-                if (response.length === 0) {
-                    $('#filter-services .results').append(
-                        $('<em/>', {
-                            'text': App.Lang.no_records_found
-                        })
-                    );
-                } else if (response.length === this.filterLimit) {
-                    $('<button/>', {
-                        'type': 'button',
-                        'class': 'btn btn-outline-secondary w-100 load-more text-center',
-                        'text': App.Lang.load_more,
-                        'click': function () {
-                            this.filterLimit += 20;
-                            this.filter(keyword, selectId, display);
-                        }.bind(this)
-                    }).appendTo('#filter-services .results');
-                }
-
-                if (selectId) {
-                    this.select(selectId, display);
-                }
-            }.bind(this)
-        );
-    };
+            if (selectId) {
+                select(selectId, show);
+            }
+        });
+    }
 
     /**
      * Get Filter HTML
@@ -381,10 +317,10 @@
      *
      * @return {String} The HTML code that represents the record on the filter results list.
      */
-    ServicesHelper.prototype.getFilterHtml = function (service) {
-        var name = service.name;
+    function getFilterHtml(service) {
+        const name = service.name;
 
-        var info = service.duration + ' min - ' + service.price + ' ' + service.currency;
+        const info = service.duration + ' min - ' + service.price + ' ' + service.currency;
 
         return $('<div/>', {
             'class': 'service-row entry',
@@ -400,32 +336,65 @@
                 $('<br/>')
             ]
         });
-    };
+    }
 
     /**
      * Select a specific record from the current filter results. If the service id does not exist
      * in the list then no record will be selected.
      *
      * @param {Number} id The record id to be selected from the filter results.
-     * @param {Boolean} display Optional (false), if true then the method will display the record on the form.
+     * @param {Boolean} show Optional (false), if true then the method will display the record on the form.
      */
-    ServicesHelper.prototype.select = function (id, display) {
-        display = display || false;
-
+    function select(id, show = false) {
         $('#filter-services .selected').removeClass('selected');
 
         $('#filter-services .service-row[data-id="' + id + '"]').addClass('selected');
 
-        if (display) {
-            var service = this.filterResults.find(function (filterResult) {
+        if (show) {
+            const service = filterResults.find(function (filterResult) {
                 return Number(filterResult.id) === Number(id);
             });
 
-            this.display(service);
+            display(service);
 
             $('#edit-service, #delete-service').prop('disabled', false);
         }
-    };
+    }
 
-    window.ServicesHelper = ServicesHelper;
+    /**
+     * Update the service category list box.
+     *
+     * Use this method every time a change is made to the service categories db table.
+     */
+    function updateAvailableCategories() {
+        App.Http.Categories.search('', 999).then((response) => {
+            var $select = $('#service-category');
+
+            $select.empty();
+
+            response.forEach(function (category) {
+                $select.append(new Option(category.name, category.id));
+            });
+
+            $select.append(new Option('- ' + App.Lang.no_category + ' -', '')).val('');
+        });
+    }
+
+    function init() {
+        resetForm();
+        filter('');
+        bindEventHandlers();
+        updateAvailableCategories();
+    }
+
+    document.addEventListener('DOMContentLoaded', init);
+
+    return {
+        filter,
+        save,
+        remove,
+        getFilterHtml,
+        resetForm,
+        select
+    };
 })();