Minor - format code.

main/inc/ajax/chat.ajax.php

@@ -1,5 +1,6 @@
 <?php
 /* For licensing terms, see /license.txt */
+
 /**
  * Responses to AJAX calls
  */
@@ -31,7 +32,7 @@ if (!isset($_SESSION['openChatBoxes'])) {
 
 $chat = new Chat();
 if ($chat->is_chat_blocked_by_exercises()) {
-    //Desconnecting the user
+    //Disconnecting the user
     $chat->set_user_status(0);
     exit;
 }