JS下拉菜单一调用，连主菜单都hover后才显示了,该如何处理

<div id="menubg">
        <div id="menu">
            <ul>
                <li><a href="#">网站首页</a></li>
                <li><a href="#">公司简介</a>
                <ul>
                    <li><a href="#">走进长顺</a></li>
                    <li><a href="#">企业理念</a></li>
                    <li><a href="#">企业荣誉</a></li>
                </ul>
                </li>
                <li><a href="#">企业动态</a></li>
                <li><a href="#">产业产品</a>
                    <ul>
                    <li><a href="#">肉鸡</a></li>
                    <li><a href="#">冷冻产品</a></li>
                    <li><a href="#">肉品加工厂</a></li>
                </ul>
                </li>
                <li><a href="#">行业知识</a></li>
                <li><a href="#">养殖现场</a></li>
                <li><a href="#">服务中心</a>
                    <ul>
                    <li><a href="#">合作社</a></li>
                    <li><a href="#">农户</a></li>
                </ul>

                </li>
                <li><a href="#">留言反馈</a></li>
                <li><a href="#">联系长顺</a></li>
            </ul>
        </div>
    </div>
         <script type="text/javascript">
        var menu=new menu.dd("menu");
        menu.init("menu","menuhover");
    </script>

#menubg {
    width: 100%;
    height: 36px;
    background: url(menubg.gif) repeat-x;
    CLEAR: both;
}
#menu {
    width: 983px;
    height: 36px;
}
#menu ul {
    line-height: 33px;
    font-size: 14px;
}
#menu ul li {
    POSITION: relative;
    float: left;
    text-align: center;
    width: 94px;
    background: url(menuline.gif) no-repeat;
    height: 36px;
    padding-left: 2px;
}
#menu ul li a {
    display: block;
    width: 90px;
    text-decoration: none;
    color: #fff;
}
#menu ul li a:hover {
    text-decoration: none;
    color: #fff;
    background: url(mhover.gif) no-repeat;
}
#menu UL LI UL {
    POSITION: absolute;
    PADDING-BOTTOM: 0px;
    PADDING-LEFT: 0px;
    WIDTH: auto;
    PADDING-RIGHT: 0px;
    DISPLAY: none;
    HEIGHT: auto;
    TOP: 36px;
    PADDING-TOP: 0px;
    LEFT: 0px;
    opacity: 1;
}
#menu UL LI UL LI {
    TEXT-ALIGN: center;
    MARGIN: 0px;
    PADDING-LEFT: 0px;
    WIDTH: auto;
    BACKGROUND: none transparent scroll repeat 0% 0%;
    FLOAT: none;
}
#menu UL LI UL LI A {
    FILTER: alpha(opacity=60);
    ZOOM: 1;
    DISPLAY: block;
    BACKGROUND: #069;
    COLOR: #fff;
    opacity: 0.6;
    -moz-opacity: 0.6;
}
#menu UL LI UL LI A:hover {
    FILTER: alpha(opacity=70);
    BACKGROUND: #006600;
    COLOR: #fff;
    opacity: 0.7;
    -moz-opacity: 0.7;
}

var menu=function(){
    var t=15,z=50,s=10,a;
    function dd(n){this.n=n; this.h=[]; this.c=[]}
    dd.prototype.init=function(p,c){
        a=c; var w=document.getElementById(p), s=w.getElementsByTagName('ul'), l=s.length, i=0;
        for(i;i<l;i++){
            var h=s[i].parentNode; this.h[i]=h; this.c[i]=s[i];
            h.onmouseover=new Function(this.n+'.st('+i+',true)');
            h.onmouseout=new Function(this.n+'.st('+i+')');
        }
    }
    dd.prototype.st=function(x,f){
        var c=this.c[x], h=this.h[x], p=h.getElementsByTagName('a')[0];
        clearInterval(c.t); c.style.overflow='hidden';
        if(f){
            p.className+=' '+a;
            if(!c.mh){c.style.display='block'; c.style.height=''; c.mh=c.offsetHeight; c.style.height=0}
            if(c.mh==c.offsetHeight){c.style.overflow='visible'}
            else{c.style.zIndex=z; z++; c.t=setInterval(function(){sl(c,1)},t)}
        }else{p.className=p.className.replace(a,''); c.t=setInterval(function(){sl(c,-1)},t)}
    }
    function sl(c,f){
        var h=c.offsetHeight;
        if((h<=0&&f!=1)||(h>=c.mh&&f==1)){
            if(f==1){c.style.filter=''; c.style.opacity=1; c.style.overflow='visible'}
            clearInterval(c.t); return
        }
        var d=(f==1)?Math.ceil((c.mh-h)/s):Math.ceil(h/s), o=h/c.mh;
        c.style.opacity=o; c.style.filter='alpha(opacity='+(o*100)+')';
        c.style.height=h+(d*f)+'px'
    }
    return{dd:dd}
}();