#menu {
width:1000px;
height:30px;
border-top:5px solid #FFFFFF;
border-bottom:5px solid #FFFFFF;
background-color:#FFFFFF;
margin: 0 auto;
display:block;
float:left;
margin-bottom:60px;
margin-top:20px;
}

#menu ul {
 margin:0;
 padding:0;
 list-style-type:none;
 text-align:center;
 background-color:lime;
 }
#menu li {
 float:left;
 margin:auto;
 padding:0;
 }
#menu li a {
 display:block; 
 width:160px;
height:30px;
background: url(images/boutton.jpg) no-repeat;
 color:white;
 text-decoration:none;
background-color:#78d001;
 margin-left:5px;
 text-align:center;
font-family: Georgia, "Times New Roman", Times, serif;
font-size:18px;
font-weight:bold;
 }
#menu li a:hover {
 color:#FFFFFF;
 width:160px;
height:30px;
background: url(images/bouttonh.jpg) no-repeat;
 margin-left:5px;
 text-align:center;
font-family: Georgia, "Times New Roman", Times, serif;
font-size:18px;
font-weight:bold;
 }

#menu ul li ul {
 display:none; 
 background-color:transparent; 
 border:5px solid #FFFFFF;
 width:160px;
 }
#menu ul li:hover ul {
 display:block;
 }
#menu li:hover ul li.millieu {
 float:none;
 border-bottom:5px solid #FFFFFF;
 margin-left:-5px;
 }
#menu li:hover ul li {
 float:none;
 margin-left:-5px;
 }

</style>
<!--[if !IE]> <-->
<style type="text/CSS">
#menu li ul {
position:absolute;
}
</style>
<!--> <![endif]-->
<!--[if IE 8]>
<style type="text/CSS">
#menu li ul {
position:absolute;
}
</style>
<![endif]-->