#menu {
width: 500px;
background: #ffffff;
float: left;
margin: 0;
padding: 0;
}
#menu ul {
list-style: none;
margin: 0;
padding: 0;
width: 7.8em;
float: left;
}

#menu a, #menu h2 {
font: bold 15px/15px helvetica, arial,  sans-serif;
display: block;
border-width: 1px;
border-style: solid;
border-color: #ccc #888 #555 #bbb;
margin: 0;
padding: 6px 4px;
}

#menu h2 {
color: #667;
background: #DDE; 
font: bold 15px arial, helvetica, sans-serif;
}
#menu a {
color: #448;
background: #efefef;
text-decoration: none;
}

#menu a:hover {
color: #a00;
background: #fff;
}

#menu li {position: relative;}

#menu ul ul ul {
position: absolute;
top: 0;
left: 100%;
}

#menu ul ul {
position: absolute;
z-index: 500;
}

div#menu ul ul {
display: none;
}

div#menu ul li:hover ul
{display: block;}

div#menu ul ul,
div#menu ul li:hover ul ul,
div#menu ul ul li:hover ul ul
{display: none;}

div#menu ul li:hover ul,
div#menu ul ul li:hover ul,
div#menu ul ul ul li:hover ul
{display: block;}

body {
behavior: url(csshover3.htc);
}

<!--[if IE]>
<style type="text/css" media="screen">
body {
behavior: url(csshover3.htc);
font-size: 100%;
}

#menu ul li {float: left; width: 100%;}
#menu ul li a {height: 1%;} 

#menu a, #menu h2 {
font: bold 0.7em/0.6em arial, helvetica, sans-serif;
}
</style>
<![endif]>