function windowopen(server,imgf,imgt,imgd,w,h) {
	if (w==null) Width=800
	else Width=w
	if (h==null) Height=600
	else Height=h
	Opt = "toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,width="+Width+",height="+Height
	Url="http://"+server+"/?imgf="+imgf+"&imgt="+imgt+"&imgd="+imgd
	var popup=window.open(Url,'finestra',Opt); 
	popup.focus(); 
}