function onoff ($id) {
  if (document.getElementById)
  {
    if (document.getElementById($id).style.visibility == "visible")
    {
	    document.getElementById($id).style.display = "none";
	    document.getElementById($id).style.visibility = "collapse";
	    document.getElementById($id).style.visibility = "hidden";
    } else
    {
	    document.getElementById($id).style.visibility = "visible";
    }
  }
}