function show (id) {
       var layer = document.getElementById(id);
  if (layer.style.visibility=='visible')
  {
   hide(id);
   return;
  }
               layer.style.visibility='visible';
   layer.style.height='';
   layer.style.width='';
   layer.style.position='relative';
   } 
   function hide (id) {
       var layer = document.getElementById(id);
               layer.style.visibility='hidden';
   layer.style.height='0px';
   layer.style.width='0px';
   layer.style.position='absolute';
   }