鼠标滑过显示隐藏层

鼠标滑过文字时显示隐藏层,隐藏层上放的是新闻,可在在隐藏层上操作点击新闻.
<script>
function ddd(obj, sType) {
var oDiv = document.getElementById(obj);
if (sType == 'show') { oDiv.style.display = 'block';}
if (sType == 'hide') { oDiv.style.display = 'none';}
}
</script>
<a href="#" onmouseover="ddd('aa', 'show');" onmouseout="ddd('aa', 'hide');">显示</a>
<a href="#" onmouseover="ddd('bb', 'show');" onmouseout="ddd('bb', 'hide');">显示</a>

<div style="display:none;" id="aa">
<a href="#">bb </a>
<a href="#">bb </a>
<a href="#">bb </a>
<a href="#">bb </a>
<a href="#">bb </a>

</div>
<div style=

<script>
function ddd(obj, sType) {
var oDiv = document.getElementById(obj);
if (sType == 'show') { oDiv.style.display = 'block';}
if (sType == 'hide') { oDiv.style.display = 'none';}

}
</script>
<a href="#" onmouseover="ddd('aa', 'show');" onmouseout="ddd('aa', 'hide');">显示</a>
<a href="#" onmouseover="ddd('bb', 'show');" onmouseout="ddd('bb', 'hide');">显示</a>

<div style="display:none;" id="aa" onmouseover="ddd('aa', 'show');" onmouseout="ddd('aa', 'hide');">
<a href="#">bb </a>
<a href="#">bb </a>
<a href="#">bb </a>
<a href="#">bb </a>