function ouvrir(page){ 
window.open(page,'Lien','width=770,height=550,scrollbars=1,menubar=1,resizable=1,toolbar=1,status=1,location=1');
} 

function fenetreCent(url,nom,largeur,hauteur,options) {
var haut=(screen.height-hauteur)/2;
var Gauche=(screen.width-largeur)/2;
fencent=window.open(url,nom,"top="+haut+",left="+Gauche+",width="+largeur+",height="+hauteur+","+options);
}