function DropMenu(sender, dropObj, selected) {
   var dropObj = document.getElementById(dropObj);
   if(!dropObj) { return; }
   var top=sender.offsetTop;
   var left=sender.offsetLeft;
   while(sender=sender.offsetParent) { top+=sender.offsetTop; left+=sender.offsetLeft; }
   dropObj.style.top=top+20;
   dropObj.style.left=left;
   dropObj.style.visibility = 'visible';
   return true;
}

function HideMenu(sender, dropObj, selected) {
   var dropObj = document.getElementById(dropObj);
   if(!dropObj) { return; }
   dropObj.style.visibility = 'hidden';
   return true;
}