css 二级下拉菜单

class="menu2"
onMouseOver="this.className='menu1'"
onMouseOut="this.className='menu2'"

body{
    background-color:white;
    font-size:12px;
    font-family:Arial, Helvetica, sans-serif;
    margin:0px;
    padding:0px;
    color:white;
}
ul,li{
    margin:0px;
    padding:0px;
}
li{
    display:inline;
    list-style:none;
    list-style-position:outside;
    text-align:center;
    font-weight:bold;
    float:left;
}
a:link{
    color:#336601;
    text-decoration:none;
    float:left;
   
    padding:3px 5px 0px 5px;
}
a:visited{
    color:#336601;
    text-decoration:none;
    float:left;
    padding:3px 5px 0px 5px;
   
}
a:hover{
    color:white;
    float:left;
    padding:3px 3px 0px 20px;
   
    text-decoration:none;
    background-color:#539D26;
}
a:active{
    color:white;
    float:left;
    padding:3px 3px 0px 20px;
   
    text-decoration:none;
    background-color:#BD06B4;
}
#nav{
   
   
    border-bottom:0px;
    padding:0px 5px;
    position:absolute;
    z-index:1;
    left: 198px;
    top: 25px;
}
.list{
    line-
    text-align:left;
    padding:4px;
    font-weight:normal;
}
.menu1{
   
    height:auto;
    margin:6px 4px 0px 0px;
    border:1px solid #9CDD75;
    background-color:#F1FBEC;
    color:#336601;
    padding:6px 0px 0px 0px;
    cursor:hand;
    overflow-y:hidden;
    filter:Alpha(opacity=70);
    -moz-opacity:0.7;
}
.menu2{
   
   
    margin:6px 4px 0px 0px;
    background-color:#F5F5F5;
    color:#999999;
    border:1px solid #EEE8DD;
    padding:6px 0px 0px 0px;
    overflow-y:hidden;
    cursor:hand;
}效果图片.