function popup() {
	Hauteur=screen.height/2-250;
	Largeur=screen.width/2-180;
window.open("/description.html","Unefenetre","top="+Hauteur+",left="+Largeur+",height=370,width=560,toolbar=0,menubar=0,status=0,scrollbar=0,resizable=1,location=0");
}