CSS:
#nav li:hover ul, #nav li.over ul{display:block}
解决方法：
在<head></head>中加入这段JS即可
<script type="text/javascript">
<!--
function menuFix() {
var sfEls = document.getElementById("nav").getElementsByTagName("li");
for (var i=0; i<sfEls.length; i++) {
sfEls.onmouseover=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";
}
sfEls.onMouseDown=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";
}
sfEls.onMouseUp=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";
}
sfEls.onmouseout=function() {
this.className=this.className.replace(new RegExp("( ?|^)sfhover\\b"),
"");
}
}
}
window.onload=menuFix;
//-->
</script>
