Navi im Header =>Hintergrund verändern

<style type="text/css" media="screen">
<!--
body
{
font-family: Arial, sans-serif;
font-size: 11px;
overflow: auto;
padding: 13px;
margin: 0px;
}

ul, li
{
list-style-type: none;
padding: 0px;
margin: 0px;
}

div.menu
{
position: absolute;
z-index: 3;
top: 58px;
left: 50%;
margin-left:-8px;
width: 100%;
}

.menu li
{
width: 145px;
float: left;
}

.menu a
{ 
 
padding-top: 9px;
text-align: center;
font-weight: bold;
cursor: pointer;
margin: 0px 0px;
display: block;
 height: 100px;
width: 145px;
color: #FFFFFF;
}

.menu a:hover
{ 
}

#smenu1, #smenu2, #smenu3
{
font-size: 13px;
display: none;
width: 200px;
float: left;
}

#smenu1 a, #smenu2 a, #smenu3 a
{
 height: 25px;
font-weight: bold;
padding-top: 9px;
border-top: 0px;
cursor: pointer;
}
//-->

</style>

<script type="text/javascript">
<!--
function montre(id)
{
with (document)
{
if (getElementById)
getElementById(id).style.display = 'block';
else if (all)
all[id].style.display = 'block';
else
layers[id].display = 'block';
}
}

function cache(id)
{
with (document)
{
if (getElementById)
getElementById(id).style.display = 'none';
else if (all)
all[id].style.display = 'none';
else
layers[id].display = 'none';
}
}
//-->
</script>