function popup(lien,larg,haut){

var top=(screen.height-haut)/2;
var left=(screen.width-larg)/2;

window.open(lien,"","top="+top+",left="+left+",width="+larg+",height="+haut+",toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no");
}