function fond(){
	var largeur_ecran = screen.width;
	var hauteur_ecran = screen.height;
	var gauche = (largeur_ecran - 1024)/2;
	var haut = (hauteur_ecran - 768)/2;
	
	document.getElementById('animation').style.position = "absolute";
	document.getElementById('animation').style.float = "left";
	document.getElementById('animation').style.width = "1024px";
	document.getElementById('animation').style.height = "768px";
	document.getElementById('animation').style.left = gauche;
	document.getElementById('animation').style.top = haut;
}