activity indicator

activity indicator

I have an add to favorites image button that when clicked changes it's icon to unmark, posts to a php page, and displays a finished message when done. I wanted to also include an activity indicator, a spinner, throbber, whatever they are called. Everything works but my indicator. The indicator is just a div with the animated indicator, and a display of none. Any advice or suggestions are greatly appreciated. I think i have included the relevent code below. If not let me know.

maddogandnoriko

Jquery CODE:
         $('.toggleFav').click(function(){
            var $this = $(this);
            $(this).iflip('images/buttons/plus.png','images/buttons/close.png');
        var $seriesid = $(this).attr('id').split('_');
               
        if ($this.is('.notFav')) {
               $this.removeClass('notFav').addClass('isFav');   
               //make the POST request
               $.post('markfavorite.php', {action:"markfav", seriesid: $seriesid[1], user_id: $seriesid[2]  }, function(data) {
                
                 $.jGrowl(data);
               });               
            
            } else if ($this.is('.isFav')) {
               $this.removeClass('isFav').addClass('notFav');
               //make the POST request
               $.post('markfavorite.php', {action:"unmarkfav", seriesid: $seriesid[1], user_id: $seriesid[2]  }, function(data) {
                 //$("#status p").html(data);
                 $.jGrowl(data);
               });               
            }
            
         }).ajaxStart(function(){
        $('#loading').show();
      });      


THE BUTTON:

           <img src="images/buttons/plus.png" class="toggleFav notFav" id="seriesid_{$show_id}"/>


INDICATOR CSS:
div.loading{
  display:none;
}