Aide Js, Css

<script type="text/javascript">
<!--
window.onload=montre;
function montre(id) {
var d = document.getElementById(id);
	for (var i = 1; i<=10; i++) {
		if (document.getElementById('smenu'+i)) {document.getElementById('smenu'+i).style.display='none';}
	}
if (d) {d.style.display='block';}
}
//-->
</script>

<style type="text/css" media="screen">
<!-- 
body {
margin: 0;
padding: 0;
font: 80% verdana, arial, sans-serif;
}
dl, dt, dd, ul, li {
margin: 0;
padding: 0;
list-style-type: none;
}
#menu {
position: relative; /* placement du menu, à modifier selon vos besoins */
top: 0;
left: 0;
z-index:100;
width: 100%; /* correction pour Opera */
}
#menu dl {
float: left;
width: 12em;
}
#menu dt {
cursor: pointer;
text-align: center;
font-weight: bold;
background: #ccc;
border: 1px solid gray;
margin: 1px;
}
#menu dd {
display: none;
border: 1px solid gray;
}
#menu li {
text-align: center;
background: #fff;
}
#menu li a, #menu dt a {
color: #000;
text-decoration: none;
display: block;
height: 100%;
border: 0 none;
}
#menu li a:hover, #menu li a:focus, #menu dt a:hover, #menu dt a:focus {
background: #eee;
}
#site {
position: absolute;
}
-->
</style>

echo'<tr>';
echo'<td width="100%" bgcolor="#336699" style="border-left-style: solid; border-left-width: 1; border-bottom-style: solid; border-bottom-width: 1" height="24">';
?>


<div id="menu">
	<dl>

		<dt onmouseover="javascript:montre();"><a href="" title="Retour à l'accueil">Accueil</a></dt>
	</dl>
	
	<dl>			
		<dt onmouseover="javascript:montre('smenu1');">Menu 1</dt>

		<dd id="smenu1" onmouseover="javascript:montre('smenu1');" onmouseout="javascript:montre('');">
			<ul>
				<li><a href="#">Sous-Menu 1.1</a></li>
				<li><a href="#">Sous-Menu 1.2</a></li>
				<li><a href="#">Sous-Menu 1.3</a></li>
				<li><a href="#">Sous-Menu 1.4</a></li>
				<li><a href="#">Sous-Menu 1.5</a></li>
				<li><a href="#">Sous-Menu 1.6</a></li>
				</ul>
		</dd>
	</dl>
	


<?
echo'</td>';
echo'</tr>';