$("ul.ad li").live('click', function(){

  data              = $(this).attr('id').replace('ad_', '');
  var url_address   = "http://"+window.location.hostname+"/modules/ad/updateClicks.php?";
  var post_data     = "adID="+data;
  
  $.ajax({
        type: 'POST',
        url:   url_address,
        data:  post_data,
        success: function(data) {
             // alert(data);
        }
        , error: function(data) {
             // alert(data);
        }                 
   });
   //return false;
});