treetable_callbacks['eventRowStateChanged'] = 'treetable_eventRowChanged';
    
    function treetable_eventRowChanged(rowId, state) {
      img = document.getElementById(rowId).getElementsByTagName('td')[0].getElementsByTagName('img')[0];
      if (state == 1) {
        img.src = 'images/nav/foldoutmenu2_arrow_open.gif';
      } else {
        img.src = 'images/nav/foldoutmenu2_arrow.gif';
      }
      return (true);
    }