function browser()
	{
	var typ;
	typ=navigator.userAgent;
	if (typ.indexOf('Opera')!=-1)
		return "O"
	if (typ.indexOf('MSIE')!=-1)
		return "IE"
	if (typ.indexOf('Mozilla')!=-1)
		return "N"
	}

	function browserv()
	{
	var ver;
	var pos;
	if (browser()=="O")
		{
		ver=navigator.userAgent
		pos=ver.indexOf("Opera")
		return ver.substring(pos+6,pos+10)
		}
	if (browser()=="IE")
		{
		ver=navigator.userAgent
		pos=ver.indexOf("MSIE")
		return ver.substring(pos+5,pos+8)
		}
	if (browser()=="N")
		{
		return navigator.appVersion;
		}
	}

	function imgset(imgName,newimg)
	{
	if (!(browser()=="N" && parseFloat(browserv())<3)) // netscape va solo dalla 3 in poi
		{
		document[imgName].src=newimg;
		}
	}