function tierMenu(objMenu,objImage)
{
  var myElement = document.getElementById(objMenu,objImage); 
  if (myElement.style.display == "none")
   {
    myElement.style.display = "";
    objImage.src = "less.gif";
   }
    else
   {
    myElement.style.display = "none";
    objImage.src = "more.gif";
   }
}