var panels = new Array('panel1', 'panel2', 'panel3', 'panel4');
      var selectedTab = null;
      function showPanel(tab, name)
      {
       
        selectedTab = tab;

        for(i = 0; i < panels.length; i++)
        {
          document.getElementById(panels[i]).style.display = (name == panels[i]) ? 'block':'none';
        }
        return false;
      }