var docI= document.getElementById;
var docL= document.layers;
var docA= document.all;

function getObj(ref){
  return ( (docI && document.getElementById(ref)) ? document.getElementById(ref) :
	   (docA && document.all[ref])            ? document.all[ref]            :
	   (docL && document.layers[ref])         ? document.layers[ref]         : null);
}

function Switch(ref) {
   obj=getObj(ref);
   visible=(obj.style.display!="none");
   if(visible != '') {
	 obj.style.display="none";
   } else {
	  obj.style.display="block";
   }
}