body {behavior: url(/css/csshover.htc);}
div#menu ul {padding: 0; margin:0px;}
div#menu li.sousmenu {}
div#menu ul li {position:relative; list-style: none; }
div#menu ul ul {position: absolute; top: 0; left: 126px; display:none}
div#menu li a {text-decoration: none;}
div#menu ul.niveau1 li.sousmenu:hover ul.niveau2, 
div#menu ul.niveau2 li.sousmenu:hover ul.niveau3 {display:block; z-index: 30;}