function openwindow(x1,y1,file,nom)
{	var floater = null;
	var chaine = 'width='+x1+',height='+y1+',toolbars=no,location=no,directories=no,status=no,menubar=no,resizable=no,scrollbars=no';
	floater=window.open(file,nom,chaine);
	floater.moveTo(((screen.width / 2) - ((x1 / 2)+5)), ((screen.height / 2) - ((y1 / 2)+30)));
	}