i1 = new Image;
	i1.src = "img/nav_materiel_over.gif";
	i2 = new Image;
	i2.src = "img/nav_references_over.gif";
	i3 = new Image;
	i3.src = "img/nav_tarifs_over.gif";
	i4 = new Image;
	i4.src = "img/nav_contacts_over.gif";
	i5 = new Image;
	i5.src = "img/nav_mastering_online_over.gif";