简单的遮隐层效果为什么出不来帮忙看下代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.<html xmlns="http://www.
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
function showsubmenu(sid)
{
whichEl = eval("submenu" + sid);
imgmenu = eval("imgmenu" + sid);
if (whichEl.style.display == "none")
{
eval("submenu" + sid + ".style.display=\"\";");
}
else
{
eval("submenu" + sid + ".style.display=\"none\";");
}
}
</script>
</head>
<body>
<div>
<div>
<table>
<tr>
<td id="imgmenu1" onClick="showsubmenu(1)" style="cursor:hand;">公司信息</td>
</tr>
<tr style="display:none;">
<td id="submenu1">
<div>
<table>
<tr>
<td>sfsdfsd</td>
<td>sfsdfsd</td>
<td>sfsdfsd</td>
</tr>
</table>
</div>
</td>
</tr>
</table>
</div>
</div>
</body>
</html>
程序代码：