diff --git a/doc/thesis/includes/headers.tex b/doc/thesis/includes/headers.tex
index f8d95c10..e223ee25 100644
--- a/doc/thesis/includes/headers.tex
+++ b/doc/thesis/includes/headers.tex
@@ -47,7 +47,7 @@
   emph            =[1]{php},
   emphstyle       =[1]\color{black},
   emph            =[2]{if,and,or,else,public,function,try,catch,return},
-  emphstyle       =[2]\color{dkyellow},
+  emphstyle       =[2]\color{dkblue},
   numbers		  = left,
   tabsize		  = 2,
   backgroundcolor = \color{ltgrey},
diff --git a/doc/thesis/snippets/google_sync_algorithm.php b/doc/thesis/snippets/google_sync_algorithm.php
index 2deba89d..71fc6200 100644
--- a/doc/thesis/snippets/google_sync_algorithm.php
+++ b/doc/thesis/snippets/google_sync_algorithm.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Complete synchronization of appointments between Google Calendar 
- * and Easy!Appointments.
+ * Complete synchronization of appointments between Google 
+ * Calendar and Easy!Appointments.
  * 
  * This method will completely sync the appointments of a provider 
  * with his Google Calendar account. The sync period needs to be 
@@ -34,8 +34,8 @@ public function sync($provider_id = NULL) {
 		$google_sync = $this->providers_model
 				->get_setting('google_sync', $provider['id']);
 		if (!$google_sync) {
-			throw new Exception('The selected provider has not the '
-					. 'google synchronization setting enabled.');
+			throw new Exception('The selected provider has not the  '
+					. 'Google synchronization setting enabled.');
 		}
 		
 		$google_token = json_decode($this->providers_model
@@ -43,66 +43,75 @@ public function sync($provider_id = NULL) {
 		$this->load->library('google_sync');
 		$this->google_sync->refresh_token($google_token->refresh_token);
 		
-		// Fetch provider's appointments that belong to the
-		// sync time period. 
+		// Fetch provider's appointments that belong to the sync 
+		// time period. 
 		$sync_past_days = $this->providers_model
 				->get_setting('sync_past_days', $provider['id']);
 		$sync_future_days = $this->providers_model
 				->get_setting('sync_future_days', $provider['id']);
-		$start = strtotime('-' . $sync_past_days . ' days', 
-				strtotime(date('Y-m-d')));
-		$end = strtotime('+' . $sync_future_days . ' days', 
-				strtotime(date('Y-m-d')));
+		$start = strtotime('-' . $sync_past_days 
+				. ' days', strtotime(date('Y-m-d')));
+		$end = strtotime('+' . $sync_future_days 
+				. ' days', strtotime(date('Y-m-d')));
 		
 		$where_clause = array(
 			'start_datetime >=' => date('Y-m-d H:i:s', $start),
 			'end_datetime <=' => date('Y-m-d H:i:s', $end),
-			'id_users_provider' => $provider['id'],
-			'is_unavailable' => FALSE
+			'id_users_provider' => $provider['id']
 		);
 		
-		$appointments = $this->appointments_model
-				->get_batch($where_clause);
+		$appointments = 
+				$this->appointments_model->get_batch($where_clause);
 		
 		$company_settings = array(
-			'company_name' => 
-				$this->settings_model->get_setting('company_name'),
-			'company_link' => 
-				$this->settings_model->get_setting('company_link'),
-			'company_email' => 
-				$this->settings_model->get_setting('company_email')
+			'company_name' => $this->settings_model
+					->get_setting('company_name'),
+			'company_link' => $this->settings_model
+					->get_setting('company_link'),
+			'company_email' => $this->settings_model
+					->get_setting('company_email')
 		);
 		
-		// Sync each appointment with Google Calendar by following
+		// Sync each appointment with Google Calendar by following 
 		// the project's sync protocol (see documentation).
 		foreach($appointments as $appointment) {
-			$service = $this->services_model
-					->get_row($appointment['id_services']);
-			$customer = $this->customers_model
-					->get_row($appointment['id_users_customer']);
+			if ($appointment['is_unavailable'] == FALSE) {
+				$service = $this->services_model
+						->get_row($appointment['id_services']);
+				$customer = $this->customers_model
+						->get_row($appointment['id_users_customer']);
+			} else {
+				$service = NULL;
+				$customer = NULL;
+			}
 
 			// If current appointment not synced yet, add to gcal.
 			if ($appointment['id_google_calendar'] == NULL) {
 				$google_event = $this->google_sync
-						->add_appointment($appointment, $provider, $service, 
-						$customer, $company_settings);
+						->add_appointment($appointment, $provider,
+						$service, $customer, $company_settings);
 				$appointment['id_google_calendar'] = $google_event->id;
-				$this->appointments_model->add($appointment); // Save gcal id
+				$this->appointments_model->add($appointment);// Save gcal id
 			} else {
 				// Appointment is synced with google calendar.
 				try {
 					$google_event = $this->google_sync
 							->get_event($appointment['id_google_calendar']);
 					
-					// If gcal event is different from e!a appointment then 
-					// update Easy!Appointments record.
+					if ($google_event->status == 'cancelled') {
+						throw new Exception('Event is cancelled, remove the '
+								. 'record from Easy!Appointments.');
+					}
+					
+					// If gcal event is different from e!a appointment 
+					// then update e!a record.
 					$is_different = FALSE;
 					$appt_start = strtotime($appointment['start_datetime']);
 					$appt_end = strtotime($appointment['end_datetime']);
 					$event_start = 
-							strtotime($google_event->getStart()->getDateTime());
+						strtotime($google_event->getStart()->getDateTime());
 					$event_end = 
-							strtotime($google_event->getEnd()->getDateTime());
+						strtotime($google_event->getEnd()->getDateTime());
 
 					if ($appt_start != $event_start 
 							|| $appt_end != $event_end) {
@@ -146,7 +155,6 @@ public function sync($provider_id = NULL) {
 					'id_users_customer' => NULL,
 					'id_services' => NULL,
 				);
-				
 				$this->appointments_model->add($appointment);
 			}
 		}
diff --git a/doc/thesis/snippets/provider_available_periods.php b/doc/thesis/snippets/provider_available_periods.php
index 157835ec..86504815 100644
--- a/doc/thesis/snippets/provider_available_periods.php
+++ b/doc/thesis/snippets/provider_available_periods.php
@@ -6,16 +6,16 @@
  * This method is very important because there are many cases where 
  * the system needs to know when a provider is avaible for an 
  * appointment. This method will return an array that belongs to the 
- * selected date and contains values that have the start and the end 
+ * selected date and contains values that have the start and the end
  * time of an available time period.
  * 
  * @param numeric $provider_id The provider's record id.
- * @param string $selected_date The date to be checked (MySQL  
+ * @param string $selected_date The date to be checked (MySQL 
  * formatted string).
- * @param array $exclude_appointments This array contains the ids of  
- * the appointments that will not be taken into consideration when   
- * the available time periods are calculated.
- * @return array Returns an array with the available time periods of  
+ * @param array $exclude_appointments This array contains the ids of 
+ * the appointments that will not be taken into consideration when the 
+ * available time periods are calculated.
+ * @return array Returns an array with the available time periods of 
  * the provider.
  */
 private function get_provider_available_time_periods($provider_id,  
@@ -28,16 +28,15 @@ private function get_provider_available_time_periods($provider_id,
 			->get_setting('working_plan', $provider_id), true);
 	
 	$where_clause = array(
-		'DATE(start_datetime)' => 
-				date('Y-m-d', strtotime($selected_date)),
-		'id_users_provider' => $provider_id
+		'DATE(start_datetime)'=>date('Y-m-d', strtotime($selected_date)),
+		'id_users_provider'=>$provider_id
 	);     
 	
-	$reserved_appointments = 
-			$this->appointments_model->get_batch($where_clause);
+	$reserved_appointments = $this->appointments_model
+			->get_batch($where_clause);
 	
 	// Sometimes it might be necessary to not take into account some 
-	// appointment records in order to display what the providers' 
+	// appointment records in order to display what the providers'
 	// available time periods would be without them.
 	foreach ($exclude_appointments as $excluded_id) {
 		foreach ($reserved_appointments as $index => $reserved) {
@@ -47,12 +46,11 @@ private function get_provider_available_time_periods($provider_id,
 		}
 	}
 	
-	// Find the empty spaces on the plan. The first split between 
-	// the plan is due to a break (if exist). After that every 
-	// reserved appointment is considered to be a taken space in the
-	// plan.
+	// Find the empty spaces on the plan. The first split between the 
+	// plan is due to a break (if exist). After that every reserved 
+	// appointment is considered to be a taken space in the plan.
 	$selected_date_working_plan = 
-		$working_plan[strtolower(date('l', strtotime($selected_date)))];
+			$working_plan[strtolower(date('l', strtotime($selected_date)))];
 	$available_periods_with_breaks = array();
 	
 	if (isset($selected_date_working_plan['breaks'])) {
@@ -65,8 +63,8 @@ private function get_provider_available_time_periods($provider_id,
 				$start_hour = $selected_date_working_plan['start'];
 				$end_hour = $break['start'];
 			} else {
-				$start_hour = $selected_date_working_plan
-						['breaks'][$last_break_index]['end'];
+				$start_hour = $selected_date_working_plan['breaks']
+						[$last_break_index]['end'];
 				$end_hour = $break['start'];
 			}
 			
@@ -75,118 +73,67 @@ private function get_provider_available_time_periods($provider_id,
 				'end' => $end_hour
 			);
 		}
-		
 		// Add the period from the last break to the end of the day.
 		$available_periods_with_breaks[] = array(
-			'start' =>$selected_date_working_plan['breaks'][$index]['end'],
-			'end' => $selected_date_working_plan['end']
+			'start'=>$selected_date_working_plan['breaks'][$index]['end'],
+			'end'=>$selected_date_working_plan['end']
 		);
 	}
 	
 	// Break the empty periods with the reserved appointments.
-	$available_periods_with_appointments = array();
+	$available_periods_with_appointments = 
+					$available_periods_with_breaks;
 	
-	if (count($reserved_appointments) > 0) {
-		
-		foreach($available_periods_with_breaks as $period) {
-			
-			foreach($reserved_appointments as $index=>$reserved) {
-				$appointment_start = 
-					date('H:i', strtotime($reserved['start_datetime']));
-				$appointment_end = 
-					date('H:i', strtotime($reserved['end_datetime']));
-				$period_start = 
-					date('H:i', strtotime($period['start']));
-				$period_end = 
-					date('H:i', strtotime($period['end']));
-				
-				if ($period_start <= $appointment_start 
-						&& $period_end >= $appointment_end) {
-					// We need to check whether another appointment fits
-					// in the current time period. If this happens, then 
-					// we need to consider the whole appointment time as 
-					// one, because the provider will not be available.
-					foreach ($reserved_appointments as $tmp_appointment) {
-						$appt_start = date('H:i', 
-							strtotime($tmp_appointment['start_datetime']));
-						$appt_end = date('H:i', 
-							strtotime($tmp_appointment['end_datetime']));
-						
-						if ($period_start < $appt_start 
-								&& $period_end > $appt_end) {
-							if ($appointment_start > $appt_start) {
-								$appointment_start = $appt_start;
-							}
-							
-							if ($appointment_end < $appt_end) { 
-								$appointment_end = $appt_end;
-							}
-						}
-					}
+	foreach($reserved_appointments as $appointment) {
+		foreach($available_periods_with_appointments as $index=>&$period){
+			$a_start = 
+				date('H:i',strtotime($appointment['start_datetime']));
+			$a_end = 
+				date('H:i', strtotime($appointment['end_datetime']));
+			$p_start = 
+				date('H:i', strtotime($period['start']));
+			$p_end = 
+				date('H:i', strtotime($period['end']));
 
-					// Current appointment is within the current 
-					// empty space. So we need to break the empty 
-					// space into two other spaces that don't include 
-					// the appointment.
-					$new_period = array(
-						'start' => $period_start,
-						'end' => $appointment_start
-					);
-					
-					if (!in_array($new_period, 
-							$available_periods_with_appointments)) {
-						$available_periods_with_appointments[] = $new_period;
-					}
-						
-					$new_period = array(
-						'start' => $appointment_end,
-						'end' => $period_end
-					);
-					
-					if (!in_array($new_period, 
-							$available_periods_with_appointments)) {
-						$available_periods_with_appointments[] = $new_period;
-					}
-					
-				} else {
-					// Check if there are any other appointments 
-					// between this time space. If not, it is going 
-					// to be added as it is.
-					$found = FALSE;
-					
-					foreach ($reserved_appointments as $tmp_appointment) {
-						$appt_start = date('H:i', 
-							strtotime($tmp_appointment['start_datetime']));
-						$appt_end  = date('H:i', 
-							strtotime($tmp_appointment['end_datetime']));
-						
-						if ($period_start < $appt_start 
-								&& $period_end > $appt_end) {
-							$found = TRUE;
-						}
-					}
-					
-					// It is also necessary to check that this time 
-					// period doesn't already exist in the 
-					// "$empty_spaces_with_appointments" array.
-					$empty_period = array(
-						'start' => $period_start,
-						'end' => $period_end
-					);
-					
-					$already_exist = in_array($empty_period, 
-							$available_periods_with_appointments);
-					
-					if ($found === FALSE && $already_exist === FALSE) {
-						$available_periods_with_appointments[] = $empty_period;
-					}
-				}
+			if ($a_start <= $p_start && $a_end <= $p_end 
+					&& $a_end <= $p_start) {
+				// The appointment does not belong in this time period, so 
+				// we will not change anything.
+			} else if ($a_start <= $p_start && $a_end <= $p_end 
+					&& $a_end >= $p_start) {
+				// The appointment starts before the period and finishes 
+				// somewhere inside.We will need to break this period and 
+				// leave the available part.
+				$period['start'] = $a_end;
+			} else if ($a_start >= $p_start && $a_end <= $p_start) {
+				// The appointment is inside the time period, so we will 
+				// split the period into two new others.
+				unset($available_periods_with_appointments[$index]);
+				$available_periods_with_appointments[] = array(
+					'start' => $p_start,
+					'end' => $a_start
+				);
+				$available_periods_with_appointments[] = array(
+					'start' => $a_end,
+					'end' => $p_end
+				);
+			} else if ($a_start >= $p_start && $a_end >= $p_start 
+					&& $a_start <= $p_end) {
+				// The appointment starts in the period and finishes out 
+				// of it. We will need to remove the time that is taken 
+				// from the appointment.
+				$period['end'] = $a_start;
+			} else if ($a_start >= $p_start && $a_end >= $p_end 
+					&& $a_start >= $p_end) {
+				// The appointment does not belong in the period so do not 
+				// change anything.
+			} else if ($a_start <= $p_start && $a_end >= $p_end 
+					&& $a_start <= $p_end) {
+				// The appointment is bigger than the period, so this period 
+				// needs to be removed.
+				unset($available_periods_with_appointments[$index]);
 			}
 		}
-	} else {
-		$available_periods_with_appointments = 
-				$available_periods_with_breaks;
 	}
-	
-	return $available_periods_with_appointments;
+	return array_values($available_periods_with_appointments);
 }
\ No newline at end of file
diff --git a/doc/thesis/thesis.pdf b/doc/thesis/thesis.pdf
index a76de7fb..d0bf701e 100644
Binary files a/doc/thesis/thesis.pdf and b/doc/thesis/thesis.pdf differ
diff --git a/rsc/misc/ebooks/listings.pdf b/rsc/misc/ebooks/listings.pdf
new file mode 100644
index 00000000..2e8f263b
Binary files /dev/null and b/rsc/misc/ebooks/listings.pdf differ
diff --git a/src/application/controllers/appointments.php b/src/application/controllers/appointments.php
index c9d28702..a7ed1e32 100644
--- a/src/application/controllers/appointments.php
+++ b/src/application/controllers/appointments.php
@@ -513,92 +513,53 @@ class Appointments extends CI_Controller {
         }
         
         // Break the empty periods with the reserved appointments.
-        $available_periods_with_appointments = array();
+        $available_periods_with_appointments = $available_periods_with_breaks;
         
-        if (count($reserved_appointments) > 0) {
+        foreach($reserved_appointments as $appointment) {
+            foreach($available_periods_with_appointments as $index => &$period) {
             
-            foreach($available_periods_with_breaks as $period) {
-                
-                foreach($reserved_appointments as $index=>$reserved) {
-                    $appointment_start = date('H:i', strtotime($reserved['start_datetime']));
-                    $appointment_end = date('H:i', strtotime($reserved['end_datetime']));
-                    $period_start = date('H:i', strtotime($period['start']));
-                    $period_end = date('H:i', strtotime($period['end']));
-                    
-                    if ($period_start <= $appointment_start && $period_end >= $appointment_end) {
-                        // We need to check whether another appointment fits in the current 
-                        // time period. If this happens, then we need to consider the whole 
-                        // appointment time as one, because the provider will not be available.
-                        foreach ($reserved_appointments as $tmp_appointment) {
-                            $appt_start = date('H:i', strtotime($tmp_appointment['start_datetime']));
-                            $appt_end = date('H:i', strtotime($tmp_appointment['end_datetime']));
-                            
-                            if ($period_start < $appt_start && $period_end > $appt_end) {
-                                if ($appointment_start > $appt_start) {
-                                    $appointment_start = $appt_start;
-                                }
-                                
-                                if ($appointment_end < $appt_end) { 
-                                    $appointment_end = $appt_end;
-                                }
-                            }
-                        }
+                $a_start = date('H:i', strtotime($appointment['start_datetime']));
+                $a_end = date('H:i', strtotime($appointment['end_datetime']));
+                $p_start = date('H:i', strtotime($period['start']));
+                $p_end = date('H:i', strtotime($period['end']));
 
-                        // Current appointment is within the current empty space. So 
-                        // we need to break the empty space into two other spaces that 
-                        // don't include the appointment.
-                        $new_period = array(
-                            'start' => $period_start,
-                            'end' => $appointment_start
-                        );
-                        
-                        if (!in_array($new_period, $available_periods_with_appointments)) {
-                            $available_periods_with_appointments[] = $new_period;
-                        }
-                            
-                        $new_period = array(
-                            'start' => $appointment_end,
-                            'end' => $period_end
-                        );
-                        
-                        if (!in_array($new_period, $available_periods_with_appointments)) {
-                            $available_periods_with_appointments[] = $new_period;
-                        }
-                        
-                    } else {
-                        // Check if there are any other appointments between this 
-                        // time space. If not, it is going to be added as it is.
-                        $found = FALSE;
-                        
-                        foreach ($reserved_appointments as $tmp_appointment) {
-                            $appt_start = date('H:i', strtotime($tmp_appointment['start_datetime']));
-                            $appt_end  = date('H:i', strtotime($tmp_appointment['end_datetime']));
-                            
-                            if ($period_start < $appt_start && $period_end > $appt_end) {
-                                $found = TRUE;
-                            }
-                        }
-                        
-                        // It is also necessary to check that this time period doesn't
-                        // already exist in the "$empty_spaces_with_appointments" array.
-                        $empty_period = array(
-                            'start' => $period_start,
-                            'end' => $period_end
-                        );
-                        
-                        $already_exist = in_array($empty_period, $available_periods_with_appointments);
-                        
-                        if ($found === FALSE && $already_exist === FALSE) {
-                            $available_periods_with_appointments[] = $empty_period;
-                        }
-                    }
+                if ($a_start <= $p_start && $a_end <= $p_end && $a_end <= $p_start) {
+                    // The appointment does not belong in this time period, so we
+                    // will not change anything.
+                } else if ($a_start <= $p_start && $a_end <= $p_end && $a_end >= $p_start) {
+                    // The appointment starts before the period and finishes somewhere inside.
+                    // We will need to break this period and leave the available part.
+                    $period['start'] = $a_end;
+
+                } else if ($a_start >= $p_start && $a_end <= $p_start) {
+                    // The appointment is inside the time period, so we will split the period
+                    // into two new others.
+                    unset($available_periods_with_appointments[$index]);
+                    $available_periods_with_appointments[] = array(
+                        'start' => $p_start,
+                        'end' => $a_start
+                    );
+                    $available_periods_with_appointments[] = array(
+                        'start' => $a_end,
+                        'end' => $p_end
+                    );
+
+                } else if ($a_start >= $p_start && $a_end >= $p_start && $a_start <= $p_end) {
+                    // The appointment starts in the period and finishes out of it. We will
+                    // need to remove the time that is taken from the appointment.
+                    $period['end'] = $a_start;
+
+                } else if ($a_start >= $p_start && $a_end >= $p_end && $a_start >= $p_end) {
+                    // The appointment does not belong in the period so do not change anything.
+                } else if ($a_start <= $p_start && $a_end >= $p_end && $a_start <= $p_end) {
+                    // The appointment is bigger than the period, so this period needs to be 
+                    // removed.
+                    unset($available_periods_with_appointments[$index]);
                 }
             }
-        } else {
-            $available_periods_with_appointments = $available_periods_with_breaks;
         }
         
-        return $available_periods_with_appointments;
+        return array_values($available_periods_with_appointments);
     }
     
     /**
diff --git a/src/application/controllers/google.php b/src/application/controllers/google.php
index 6e6484b8..80e95639 100644
--- a/src/application/controllers/google.php
+++ b/src/application/controllers/google.php
@@ -112,8 +112,7 @@ class Google extends CI_Controller {
             $where_clause = array(
                 'start_datetime >=' => date('Y-m-d H:i:s', $start),
                 'end_datetime <=' => date('Y-m-d H:i:s', $end),
-                'id_users_provider' => $provider['id'],
-                'is_unavailable' => FALSE
+                'id_users_provider' => $provider['id']
             );
             
             $appointments = $this->appointments_model->get_batch($where_clause);
@@ -127,8 +126,13 @@ class Google extends CI_Controller {
             // Sync each appointment with Google Calendar by following the project's sync
             // protocol (see documentation).
             foreach($appointments as $appointment) {
-                $service = $this->services_model->get_row($appointment['id_services']);
-                $customer = $this->customers_model->get_row($appointment['id_users_customer']);
+                if ($appointment['is_unavailable'] == FALSE) {
+                    $service = $this->services_model->get_row($appointment['id_services']);
+                    $customer = $this->customers_model->get_row($appointment['id_users_customer']);
+                } else {
+                    $service = NULL;
+                    $customer = NULL;
+                }
 
                 // If current appointment not synced yet, add to gcal.
                 if ($appointment['id_google_calendar'] == NULL) {
@@ -141,6 +145,10 @@ class Google extends CI_Controller {
                     try {
                         $google_event = $this->google_sync->get_event($appointment['id_google_calendar']);
                         
+                        if ($google_event->status == 'cancelled') {
+                            throw new Exception('Event is cancelled, remove the record from Easy!Appointments.');
+                        }
+                        
                         // If gcal event is different from e!a appointment then update e!a record.
                         $is_different = FALSE;
                         $appt_start = strtotime($appointment['start_datetime']);
diff --git a/src/application/libraries/google_sync.php b/src/application/libraries/google_sync.php
index e4e95f2b..6e9efe16 100644
--- a/src/application/libraries/google_sync.php
+++ b/src/application/libraries/google_sync.php
@@ -108,7 +108,7 @@ class Google_Sync {
         $this->CI->load->helper('general');
         
         $event = new Google_Event();
-        $event->setSummary($service['name']);
+        $event->setSummary(($service != NULL) ? $service['name'] : 'Unavailable');
         $event->setLocation($company_settings['company_name']);
         
         $start = new Google_EventDateTime();
@@ -119,20 +119,21 @@ class Google_Sync {
         $end->setDateTime(date3339(strtotime($appointment['end_datetime'])));
         $event->setEnd($end);
         
-        $eventProvider = new Google_EventAttendee();
-        $eventProvider->setDisplayName($provider['first_name'] . ' ' 
+        $event->attendees = array();
+        
+        $event_provider = new Google_EventAttendee();
+        $event_provider->setDisplayName($provider['first_name'] . ' ' 
                 . $provider['last_name']);
-        $eventProvider->setEmail($provider['email']);
+        $event_provider->setEmail($provider['email']);
+        $event->attendees[] = $event_provider;
         
-        $eventCustomer = new Google_EventAttendee();
-        $eventCustomer->setDisplayName($customer['first_name'] . ' ' 
-                . $customer['last_name']);
-        $eventCustomer->setEmail($customer['email']);
-        
-        $event->attendees = array(
-            $eventProvider, 
-            $eventCustomer
-        );
+        if ($customer != NULL) {
+            $event_customer = new Google_EventAttendee();
+            $event_customer->setDisplayName($customer['first_name'] . ' ' 
+                    . $customer['last_name']);
+            $event_customer->setEmail($customer['email']);
+            $event->attendees[] = $event_customer;
+        }
         
         // Add the new event to the "primary" calendar.
         $created_event = $this->service->events->insert('primary', $event);
@@ -171,20 +172,21 @@ class Google_Sync {
         $end->setDateTime(date3339(strtotime($appointment['end_datetime'])));
         $event->setEnd($end);
         
+        $event->attendees = array();
+        
         $event_provider = new Google_EventAttendee();
         $event_provider->setDisplayName($provider['first_name'] . ' ' 
                 . $provider['last_name']);
         $event_provider->setEmail($provider['email']);
+        $event->attendees[] = $event_provider; 
         
-        $event_customer = new Google_EventAttendee();
-        $event_customer->setDisplayName($customer['first_name'] . ' ' 
-                . $customer['last_name']);
-        $event_customer->setEmail($customer['email']);
-        
-        $event->attendees = array(
-            $event_provider, 
-            $event_customer
-        );
+        if ($customer != NULL) {
+            $event_customer = new Google_EventAttendee();
+            $event_customer->setDisplayName($customer['first_name'] . ' ' 
+                    . $customer['last_name']);
+            $event_customer->setEmail($customer['email']);
+            $event->attendees[] = $event_customer;
+        }
         
         $updated_event = $this->service->events->update('primary', $event->getId(), $event);
         
diff --git a/src/application/views/appointments/book.php b/src/application/views/appointments/book.php
index 4b3b4493..86a11639 100644
--- a/src/application/views/appointments/book.php
+++ b/src/application/views/appointments/book.php
@@ -133,7 +133,7 @@
                             <form id="cancel-appointment-form" method="post" 
                                     action="' . $this->config->item('base_url') 
                                     . 'appointments/cancel/' . $appointment_data['hash'] . '">
-                                <textarea name="cancel_reason" style="display:none;"></textarea>
+                                <textarea name="cancel_reason" style="display:none"></textarea>
                                 <button id="cancel-appointment" class="btn btn-inverse">
                                         Cancel</button>
                             </form>
diff --git a/src/application/views/appointments/cancel.php b/src/application/views/appointments/cancel.php
index 3a013c23..f27332b5 100644
--- a/src/application/views/appointments/cancel.php
+++ b/src/application/views/appointments/cancel.php
@@ -48,7 +48,7 @@
     <div id="success-frame" class="frame-container">
         <img id="success-icon" src="<?php echo $this->config->base_url(); ?>assets/images/success.png" />
         
-        <h3>Your appointment has been successfully canceled!</h3>
+        <h3>Your appointment has been successfully cancelled!</h3>
         
         <?php 
             // Display exceptions (if any).
diff --git a/src/application/views/backend/calendar.php b/src/application/views/backend/calendar.php
index 4fe8d479..b9320661 100644
--- a/src/application/views/backend/calendar.php
+++ b/src/application/views/backend/calendar.php
@@ -43,7 +43,7 @@
             <div class="btn-group">
                 <?php //if ($privileges[PRIV_USERS]['edit'] == TRUE) { ?>
                 <?php if (($role_slug == DB_SLUG_ADMIN || $role_slug == DB_SLUG_PROVIDER)
-                        && $this->config->item('ea_google_sync') == TRUE) { ?>
+                        && $this->config->item('ea_google_sync_feature') == TRUE) { ?>
                 <button id="google-sync" class="btn btn-primary" 
                         title="Trigger the Google Calendar synchronization process.">
                     <i class="icon-refresh icon-white"></i>
diff --git a/src/application/views/backend/customers.php b/src/application/views/backend/customers.php
index 8aa85acf..2d8912b2 100644
--- a/src/application/views/backend/customers.php
+++ b/src/application/views/backend/customers.php
@@ -65,7 +65,7 @@
             
             <div id="save-cancel-group" class="btn-group" style="display:none;">
                 <button id="save-customer" class="btn btn-primary">
-                    <i class="icon-ok"></i>
+                    <i class="icon-ok icon-white"></i>
                     Save</button>
                 <button id="cancel-customer" class="btn">
                     <i class="icon-ban-circle"></i>
diff --git a/src/application/views/backend/services.php b/src/application/views/backend/services.php
index 5d892397..d3b58661 100644
--- a/src/application/views/backend/services.php
+++ b/src/application/views/backend/services.php
@@ -67,7 +67,7 @@
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-service" class="btn btn-primary">
-                        <i class="icon-ok"></i>
+                        <i class="icon-ok icon-white"></i>
                         Save</button>
                     <button id="cancel-service" class="btn">
                         <i class="icon-ban-circle"></i>
@@ -144,7 +144,7 @@
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-category" class="btn btn-primary">
-                        <i class="icon-ok"></i>
+                        <i class="icon-ok icon-white"></i>
                         Save</button>
                     <button id="cancel-category" class="btn">
                         <i class="icon-ban-circle"></i>
diff --git a/src/application/views/backend/users.php b/src/application/views/backend/users.php
index 6294eae5..e811a9d0 100644
--- a/src/application/views/backend/users.php
+++ b/src/application/views/backend/users.php
@@ -93,7 +93,7 @@
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-admin" class="btn btn-primary">
-                        <i class="icon-ok"></i>
+                        <i class="icon-ok icon-white"></i>
                         Save</button>
                     <button id="cancel-admin" class="btn">
                         <i class="icon-ban-circle"></i>
@@ -201,7 +201,7 @@
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-provider" class="btn btn-primary">
-                        <i class="icon-ok"></i>
+                        <i class="icon-ok icon-white"></i>
                         Save</button>
                     <button id="cancel-provider" class="btn">
                         <i class="icon-ban-circle"></i>
@@ -409,7 +409,7 @@
 
                 <div class="save-cancel-group btn-group" style="display:none;">
                     <button id="save-secretary" class="btn btn-primary">
-                        <i class="icon-ok"></i>
+                        <i class="icon-ok icon-white"></i>
                         Save</button>
                     <button id="cancel-secretary" class="btn">
                         <i class="icon-ban-circle"></i>
diff --git a/src/application/views/general/installation.php b/src/application/views/general/installation.php
index 876521d0..f12e6cd9 100644
--- a/src/application/views/general/installation.php
+++ b/src/application/views/general/installation.php
@@ -195,7 +195,7 @@
         }
         
         #loading { 
-            position: absolute; 
+            position: fixed; 
             top: 0px; 
             left: 0px; 
             width: 100%; 
diff --git a/src/assets/css/backend.css b/src/assets/css/backend.css
index 432d977a..b9defede 100644
--- a/src/assets/css/backend.css
+++ b/src/assets/css/backend.css
@@ -11,7 +11,7 @@ root {
 #header {
     height: 70px;
     background-color: #35B66F;
-    border-bottom: 6px solid #247A4B;
+    border-bottom: 4px solid #247A4B;
 }
 
 #header #header-logo { 
@@ -96,7 +96,7 @@ root {
 }
 
 #loading { 
-    position: absolute; 
+    position: fixed; 
     top: 0px; 
     left: 0px; 
     width: 100%; 
@@ -178,14 +178,19 @@ body .jspTrack {
 
 #calendar-page #calendar .fc-unavailable { 
     background-image: url('../images/unavailable.jpg');   
-    font-size: 24px; 
+    font-size: 17px; 
     border-radius: 0; 
     font-weight: bold; 
     color: #333;
-    text-shadow: 0px 1px 0px #FFF;
+    text-shadow: 0px 1px 0px #E6E6E6;
     opacity: 0.7;
 }
 
+#calendar-page #calendar .fc-event-title small {
+    font-weight: normal;
+    font-size: 12px;
+}
+
 #calendar-page #calendar .fc-break { 
     background-image: url('../images/break.jpg'); 
 }
diff --git a/src/assets/js/backend_calendar.js b/src/assets/js/backend_calendar.js
index 824aaad4..3ae416a8 100644
--- a/src/assets/js/backend_calendar.js
+++ b/src/assets/js/backend_calendar.js
@@ -52,7 +52,10 @@ var BackendCalendar = {
             'dayClick': BackendCalendar.calendarDayClick,
             'eventClick': BackendCalendar.calendarEventClick,
             'eventResize': BackendCalendar.calendarEventResize,
-            'eventDrop': BackendCalendar.calendarEventDrop
+            'eventDrop': BackendCalendar.calendarEventDrop,
+            'eventAfterAllRender': function(view) {
+                BackendCalendar.convertTitlesToHtml();
+            }
         });
         
         // Temporary fix: make the first letter capital in all the lowercase strings
@@ -264,7 +267,7 @@ var BackendCalendar = {
 
                     if (response.warnings) {
                         response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                        GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                        GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                         $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                     }
                     
@@ -396,7 +399,7 @@ var BackendCalendar = {
 
                             if (response.warnings) {
                                 response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                                GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                                GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                                 $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                             }
 
@@ -437,7 +440,7 @@ var BackendCalendar = {
 
                     if (response.warnings) {
                         response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                        GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                        GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                         $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                     }
 
@@ -510,7 +513,7 @@ var BackendCalendar = {
             }
             
             // :: DEFINE SUCCESS EVENT CALLBACK
-            var successCallback = function(response) {
+            var successCallback = function(response) {                
                 if (response.exceptions) {             
                     response.exceptions = GeneralFunctions.parseExceptions(response.exceptions);
                     GeneralFunctions.displayMessageBox(GeneralFunctions.EXCEPTIONS_TITLE, GeneralFunctions.EXCEPTIONS_MESSAGE);
@@ -527,6 +530,7 @@ var BackendCalendar = {
                 $dialog.find('.modal-message').text('Appointment saved successfully!');
                 $dialog.find('.modal-message').addClass('alert-success').removeClass('alert-error');
                 $dialog.find('.modal-message').fadeIn();
+                $dialog.find('.modal-body').scrollTop(0);
                 
                 // Close the modal dialog and refresh the calendar appointments 
                 // after one second.
@@ -542,6 +546,7 @@ var BackendCalendar = {
                 $dialog.find('.modal-message').text('A server communication error occured, please try again.');
                 $dialog.find('.modal-message').addClass('alert-error');
                 $dialog.find('.modal-message').fadeIn();
+                $dialog.find('.modal-body').scrollTop(0);
             };
             
             // :: CALL THE UPDATE APPOINTMENT METHOD
@@ -600,7 +605,7 @@ var BackendCalendar = {
 
                 if (response.warnings) {
                     response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                    GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                    GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                     $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                 }
                 
@@ -913,7 +918,7 @@ var BackendCalendar = {
                                 
                                 if (calendarDateStart < workDateStart) {
                                     unavailablePeriod = {
-                                        'title': 'Unavailable',
+                                        'title': 'Not Working',
                                         'start': calendarDateStart,
                                         'end': workDateStart,
                                         'allDay': false,
@@ -932,7 +937,7 @@ var BackendCalendar = {
                                         'dd/MM/yyyy HH:mm'); // Use calendarDateStart ***
                                 if (calendarDateEnd > workDateEnd) {
                                     var unavailablePeriod = {
-                                        'title': 'Unavailable',
+                                        'title': 'Not Working',
                                         'start': workDateEnd,
                                         'end': calendarDateEnd,
                                         'allDay': false,
@@ -965,7 +970,9 @@ var BackendCalendar = {
                                 // Add custom unavailable periods.
                                 $.each(response.unavailables, function(index, unavailable) {
                                     var unavailablePeriod = {
-                                        'title': 'Unavailable',
+                                        'title': 'Unavailable <br><small>' + ((unavailable.notes.length > 30) 
+                                                        ? unavailable.notes.substring(0, 30) + '...'
+                                                        : unavailable.notes) + '</small>',
                                         'start': Date.parse(unavailable.start_datetime),
                                         'end': Date.parse(unavailable.end_datetime),
                                         'allDay': false,
@@ -991,7 +998,9 @@ var BackendCalendar = {
                                         if (currDateStart.toString('dd/MM/yyyy') 
                                             === Date.parse(unavailable.start_datetime).toString('dd/MM/yyyy')) {
                                             var unavailablePeriod = {
-                                                'title': 'Unavailable',
+                                                'title': 'Unavailable <br><small>' + ((unavailable.notes.length > 30) 
+                                                        ? unavailable.notes.substring(0, 30) + '...'
+                                                        : unavailable.notes) + '</small>',
                                                 'start': Date.parse(unavailable.start_datetime),
                                                 'end': Date.parse(unavailable.end_datetime),
                                                 'allDay': false,
@@ -1004,7 +1013,6 @@ var BackendCalendar = {
                                         }
                                     });
                                     
-                                    
                                     if (workingDay == null) {
                                         // Add a full day unavailable event.
                                         unavailablePeriod = {
@@ -1029,7 +1037,7 @@ var BackendCalendar = {
                                             + ' ' + workingDay.start, 'dd/MM/yyyy HH:mm');
                                     if (currDateStart < start) {
                                         unavailablePeriod = {
-                                            'title': 'Unavailable',
+                                            'title': 'Not Working',
                                             'start': GeneralFunctions.clone(currDateStart),
                                             'end': GeneralFunctions.clone(start),
                                             'allDay': false,
@@ -1045,7 +1053,7 @@ var BackendCalendar = {
                                             + ' ' + workingDay.end, 'dd/MM/yyyy HH:mm');
                                     if (currDateEnd > end) {
                                         unavailablePeriod = {
-                                            'title': 'Unavailable',
+                                            'title': 'Not Working',
                                             'start': GeneralFunctions.clone(end),
                                             'end': GeneralFunctions.clone(currDateEnd),
                                             'allDay': false,
@@ -1082,6 +1090,8 @@ var BackendCalendar = {
                         }   
                     } 
                 });
+                // Convert the titles to html code.
+                //BackendCalendar.convertTitlesToHtml();
             }
         }, 'json');
     },
@@ -1209,7 +1219,7 @@ var BackendCalendar = {
                 if (response.warnings) {
                     // Display warning information to the user.
                     response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                    GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                    GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                     $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                 }
 
@@ -1262,7 +1272,7 @@ var BackendCalendar = {
                 if (response.warnings) {
                     // Display warning information to the user.
                     response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                    GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                    GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                     $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                 }
 
@@ -1307,6 +1317,7 @@ var BackendCalendar = {
     calendarWindowResize: function(view) {
         $('#calendar').fullCalendar('option', 'height', 
                 BackendCalendar.getCalendarHeight());
+        //BackendCalendar.convertTitlesToHtml();        
     },
     
     /**
@@ -1476,7 +1487,7 @@ var BackendCalendar = {
                 if (response.warnings) {
                     // Display warning information to the user.
                     response.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                    GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                    GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                     $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                 }
 
@@ -1539,7 +1550,7 @@ var BackendCalendar = {
                 
                 if (response.warnings) {
                     reponse.warnings = GeneralFunctions.parseExceptions(response.warnings);
-                    GeneralFunctions.displayMessageBox(Backend.WARNINGS_TITLE, Backend.WARNINGS_MESSAGE);
+                    GeneralFunctions.displayMessageBox(GeneralFunctions.WARNINGS_TITLE, GeneralFunctions.WARNINGS_MESSAGE);
                     $('#message_box').append(GeneralFunctions.exceptionsToHtml(response.warnings));
                 }
                 
@@ -1598,8 +1609,17 @@ var BackendCalendar = {
                 $('#select-filter-item option:selected').attr('type'), 
                 $('#calendar').fullCalendar('getView').visStart,
                 $('#calendar').fullCalendar('getView').visEnd);
-        $(window).trigger('resize'); 
-
+        $(window).trigger('resize'); // Places the footer on the bottom.
+        
+        // Change string from "all-day" to "All Day".
+        $('#calendar .fc-agenda-allday .fc-agenda-axis').text('All Day');
+        
+        // Remove all open popovers.
+        $('.close-popover').each(function() {
+            $(this).parents().eq(2).remove();
+        });
+        
+        // Add new pop overs.
         $('.fv-events').each(function(index, eventHandle) {
             $(eventHandle).popover();
         });
@@ -1759,5 +1779,20 @@ var BackendCalendar = {
         
         // Clear the unavailable notes field.
         $dialog.find('#unavailable-notes').val('');
+    },
+           
+    /**
+     * On some calendar events the titles contain html markup that is not 
+     * displayed properly due to the fullcalendar plugin. This plugin sets
+     * the .fc-event-title value by using the $.text() method and not the 
+     * $.html() method. So in order for the title to display the html properly
+     * we convert all the .fc-event-titles where needed into html.
+     */
+    convertTitlesToHtml: function() {
+        // Convert the titles to html code.
+        $('.fc-custom').each(function() {
+            var title = $(this).find('.fc-event-title').text();
+            $(this).find('.fc-event-title').html(title);
+        });
     }
 };
\ No newline at end of file
diff --git a/src/assets/js/backend_customers.js b/src/assets/js/backend_customers.js
index 7a4d15d5..9a6bc0e8 100644
--- a/src/assets/js/backend_customers.js
+++ b/src/assets/js/backend_customers.js
@@ -397,13 +397,17 @@ CustomersHelper.prototype.filter = function(key, selectId, display) {
  * @return {string} Returns the record html code.
  */
 CustomersHelper.prototype.getFilterHtml = function(customer) {
+    var name = customer.first_name + ' ' + customer.last_name;
+    var info = customer.email; 
+    info = (customer.phone_number != '' && customer.phone_number != null) 
+            ? info + ', ' + customer.phone_number : info;
+    
     var html = 
             '<div class="customer-row" data-id="' + customer.id + '">' +
                 '<strong>' + 
-                    customer.first_name + ' ' + customer.last_name + 
+                    name + 
                 '</strong><br>' + 
-                '<span>' + customer.email + '</span> | ' + 
-                '<span>' + customer.phone_number + '</span>' + 
+                info +
             '</div><hr>';
     
     return html;
diff --git a/src/assets/js/frontend_book.js b/src/assets/js/frontend_book.js
index b079fd3b..27ff8129 100644
--- a/src/assets/js/frontend_book.js
+++ b/src/assets/js/frontend_book.js
@@ -214,8 +214,8 @@ var FrontendBook = {
                         + 'minute to write the reason you are cancelling the appointment:',
                         dialogButtons);
                         
-                $('#message_box').append('<textarea id="cancel-reason"></textarea>');
-                $('#cancel-reason').css('width', '300px');
+                $('#message_box').append('<textarea id="cancel-reason" rows="3"></textarea>');
+                $('#cancel-reason').css('width', '353px');
             });
         }
         
@@ -553,11 +553,15 @@ var FrontendBook = {
                 html = '<strong>' + service.name + '</strong>';
                 
                 if (service.description != '' && service.description != null) {
-                    html += '<br>' + service.description;
+                    html += '<br>' + service.description + '<br>';
+                }
+                
+                if (service.duration != '' && service.duration != null) {
+                    html += '[Duration ' + service.duration + ' Minutes] ';
                 }
                 
                 if (service.price != '' && service.price != null) {
-                    html += '<br> [Price ' + service.price + ' ' + service.currency  + ']';
+                    html += '[Price ' + service.price + ' ' + service.currency  + ']';
                 }   
                 
                 html += '<br>';
diff --git a/src/configuration.php b/src/configuration.php
index 780db7de..d3f49447 100644
--- a/src/configuration.php
+++ b/src/configuration.php
@@ -10,7 +10,7 @@ class SystemConfiguration {
     public static $db_password = '';
     
     // Google Calendar API Settings
-    public static $google_sync_feature  = FALSE; // Enter TRUE or FALSE;
+    public static $google_sync_feature  = TRUE; // Enter TRUE or FALSE;
     public static $google_product_name  = 'Easy!Appointments';
     public static $google_client_id     = '396094740598-l9ohhdgs0hr6qi89628p3chf9lm59mkc.apps.googleusercontent.com';
     public static $google_client_secret = '3kKEgx3mgxfFInrWf3jTUn4D';