Sugar for comment sending.

- Do not send if comment empty
    - Disable submit button while submit is in progress

js/app/studs.js

@@ -49,6 +49,8 @@ $(document).ready(function () {
     form.submit(function(event) {
         event.preventDefault();
 
+        if ($('#comment').val()) {
+            $('#add_comment').attr("disabled", "disabled");
             $.ajax({
                 type: 'POST',
                 url: form.attr('action'),
@@ -57,7 +59,6 @@ $(document).ready(function () {
                 success: function(data)
                 {
                     $('#comment').val('');
-
                     if (data.result) {
                         $('#comments_list')
                             .replaceWith(data.comments);
@@ -81,8 +82,12 @@ $(document).ready(function () {
                             scrollTop: commentsAlert.offset().top
                         }, 750);
                     }
+                },
+                complete: function() {
+                    $('#add_comment').removeAttr("disabled");
                 }
             });
+        }
 
         return false;
     });