javascript 弹出层的雏形

<ul><li  onmousemove="xianshi('wang')" onmouseout="yincang('wang')"><a href="#">鼠标扑捉</a><ul><li  id="wang" style=" width:200px; height:200px; background:#CCC;"> <a href="#">显示与隐藏</a></li></ul></li>
<li  onmousemove="xianshi('hh')" onmouseout="yincang('hh')"><a href="#">鼠标扑捉</a><ul><li  id="hh" style=" width:200px; height:200px; background:#CCC;"> <a href="#">显示与隐藏</a></li></ul></li>

</ul>

</div>
<script type="text/javascript">

function xianshi(emlt){
    document.getElementById(emlt).style.visibility='visible';
    }
function yincang(emlt){
    document.getElementById(emlt).style.visibility='hidden';
    }    
</script>