iframe ทับเมนู dropdown list ช่วยหน่อยนะครับช่วยหน่อยนะครับช่วยหน่อยนะครับ

* {
    padding: 0;
    margin: 0;
    text-decoration: none;
    list-style: none;
}
body {
    font: 12px/18px tahoma;
    width: 510px;
    margin: 50px auto;
}
ul[id^="thaicss-nav"]:after {
    content: " ";
    display: block;
    clear: both;
}
ul[id$="horizontal"]>li {
    float: left;
    width: 100px;
    position: relative;
    background: #f2f2f2;
    border-left: solid 1px #ccc;
}
ul[id$="horizontal"]>li:first-child {
    border-left: none;
}
ul[id|="thaicss-nav"]>li>a, ul[id|="thaicss-nav"]>li:hover>ul>li>a {
    display: block;    
    line-height: 20px;
}
ul[id|="thaicss-nav"]>li>a {
    text-align: center;
    color: #333;
}
ul[id|="thaicss-nav"]>li:hover>ul>li>a {
    color: #FFF;
}
ul[id|="thaicss-nav"]>li:hover>a, ul[id|="thaicss-nav"]>li:hover>ul>li:hover>ul>li>a {
    color: #CCC;
}
ul[id|="thaicss-nav"]>li:hover, ul[id|="thaicss-nav"]>li>ul, ul[id|="thaicss-nav"]>li:hover>ul>li>ul {
    background: #666;
}
ul[id|="thaicss-nav"]>li:hover>ul>li:hover, ul[id|="thaicss-nav"]>li:hover>ul>li:hover>ul>li:hover {
    background: #444;
}
ul[id$="horizontal"]>li>ul, ul[id$="horizontal"]>li:hover>ul>li>ul {
    visibility: hidden;
    position: absolute;
    width: 150px;
}
ul[id|="thaicss-nav"]>li:hover>ul, ul[id|="thaicss-nav"]>li:hover>ul>li:hover>ul {
    visibility: visible;
}
ul[id|="thaicss-nav"]>li:hover>ul>li, ul[id|="thaicss-nav"]>li:hover>ul>li:hover>ul>li {
    line-height: 18px;
    padding-left: 3px;
    border-bottom: solid 1px #555;
    border-top: solid 1px #999;
}
ul[id$="horizontal"]>li:hover>ul>li:hover>ul {
    left: 150px;
    margin-top: -20px;
ข้างบนเป็น css นะคับ