menu and slideshow IE 7

need add
#header-top{z-index:400;}
and modify
#main-menu li ul {
z-index: 400;
position: absolute;
left: -999em;
height: auto;
width: 170px;
margin: 1px 0px 0px 0px;
padding: 0;
}

z-index:400 <- fix conflict Overlay