function popupCentree(url,nom,largeur,hauteur,opt)
	{
		var top=(screen.height-hauteur)/2;
		var left=(screen.width-largeur)/2;
		var MyWin=window.open(url,nom,"top="+top+",left="+left+",width="+largeur+",height="+hauteur+","+opt);
		MyWin.focus();
	}