#bandeau {position: absolute; visibility: visible; z-index:0;width:730px; height:77px;  left: 40px; top: 0px;}
#retour {position: absolute; visibility: visible; z-index:0;width:40px; height:77px;  left: 0px; top: 0px;}
#menu {POSITION: absolute; VISIBILITY: visible; z-index:1;width:770px; height:25px;  left:0px; top: 75px;}