var help_popup=null;
function show_help_popup(helpid) {
  if (help_popup!=null)
  { help_popup.close(help_popup);
    help_popup=null;
  }

  help_popup=window.open("../aspx/helppopup.aspx?helpid="+helpid, "popupWindow", "menubar=0,location=0,resizable=0,scrollbars=0,status=0,width=300,height=300,left = 650,top = 450'");
  if (!help_popup.opener)
       help_popup.opener = self;
}

function show_help(layer_name, display_style)
{
  document.getElementById(layer_name).style.display=display_style;
}