//INDIVIDUAZIONE DEL BROWSER USATO
var ns4 = (navigator.appName.indexOf("Netscape")>=0 && !document.getElementById)? 1 : 0; 
var ie4 = (document.all && !document.getElementById)? 1 : 0;
var ie5 = (document.getElementById && document.all)? 1 : 0;			//IE 7
var ns6 = (document.getElementById && navigator.appName.indexOf("Netscape")>=0 )? 1: 0; //FIREFOX
var w3c = (document.getElementById)? 1 : 0;

//FUNZIONI -  GENERAL PURPOSES
function getObject(name) {
   if (w3c) return document.getElementById(name);
   if (ns4) return eval('document.' + name);
   if (ns6) return document.getElementById(name);
   if (ie4) return eval('document.all.' + name);
   if (ie5) return document.getElementById(name);
   return false
}

function swap(obj_id,img){

var obj=getObject(obj_id);

	if( obj.src != img)
	{
			obj.src=img;
	}

}