function switchDisplay(itemNo) {
  var el = document.getElementById(itemNo);

 var i=1;
 while (document.getElementById('point'+i)!=null)
 {
   if (document.getElementById('point'+i) != el)
	  {
	   document.getElementById('point'+i).style.display = 'none';
		}
	 else
	  {
    if ( el.style.display != "none" )
        el.style.display = 'none';
     else
        el.style.display = '';
 	  }
	 i++;
 }

}