function addTab(subtitle, url) { 
    if (!$('#tabs').tabs('exists', subtitle)) { 
      $('#tabs').tabs('add', { 
        title : subtitle, 
        content :<span style="font-family: Arial, Helvetica, sans-serif;">createFrame(url)</span><span style="font-family: Arial, Helvetica, sans-serif;">,</span> 
        border : false, 
        bodyCls:"indexTabBody", 
        closable : true 
      }); 
    } else { 
      $("#tabs").tabs("select", subtitle); 
      var selTab = $('#tabs').tabs('getSelected'); 
      $('#tabs').tabs('<strong>update</strong>', { 
        tab: selTab, 
        options: { 
          content:createFrame(url) 
        } 
      }) 
    } 
  } 
  function createFrame(url){ 
    return '<iframe scrolling="auto" frameborder="0" src="' +_ctx_+ url + '" style="width:100%;height:100%;"></iframe>'; 
  }