请问一个层的问题，不知道问题出在哪了

[pq16344]

一个层问题，很简单，但是我找不到问题出在哪，不响应我的onclick事件，
代码如下：
<tr>
<td height="29" valign="middle"><table width="100%" height="29" border="0" align="left" cellpadding="0" cellspacing="0"
ID="Table18">
<tbody>
<tr>
<td width="95" height="17" bgcolor="#F3F3F3">
<div align="center"></div>
<div align="center"><strong style="font-size:14px"><img height="10" alt="中国博客网(www.blogcn.com)：按纽2" src="../images/icon10.gif" width="10"> 发布中心：</strong></div>
</td>
<td onclick="turnit(bb)">
<p align="center">网络游戏 |</td>
<td width="63">
<p align="left">对战游戏
|</td>
<td width="260" class="input1">
<p align="left">
<a target="_blank" href="../newfm.asp?urlto=chooseGame.asp"> 定制最新游戏</a> |
<a href="../newfm.asp?url=upload/upload_manage.asp" target="_blank" > 图片日记</a></td>
</tr>
</tbody>
</table>
</td>
</tr>

<tr><td id="bb" style="display:none">
<div id="Layer1" style="position:absolute; left:240px; top:329px; visibility: visible">
<table width=130 cellpadding="0" cellspacing="4" ID="Table19">
<tr>
<td valign='middle' align='center' height='20' class=menuout onmouseover=this.className='menuover'; onmouseout=this.className='menuout'; >
<a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=51'>777777777777</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br></td><td><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br></td><td><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br><a href='../newfm.asp?urlto=log_ct.asp?gameID=60'>aaaaaaaaaaaaaaa</a><br></td></tr>
</table>
</div>
</td></tr>




<script lanuage="JScript">
function turnit()
{
if (document.all.bb.style.display=="none")
{
document.all.bb.style.display="block";
alert(document.all.bb.style.display);
}
}
</script>