css样式 3级 下拉菜单 不能放在table中？

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>三级dropdown弹出菜单</title>
<style type="text/css">
/* common styling */
.menu {font-family: arial, sans-serif; width:750px; position:relative; margin:0; font-size:11px; margin:50px 0;}
.menu ul li a, .menu ul li a:visited {display:block; text-decoration:none; color:#000;width:104px; height:20px; text-align:center; color:#fff; border:1px solid #fff; background:#710069; line-height:20px; font-size:11px; overflow:hidden;}
.menu ul {padding:0; margin:0;list-style-type: none; }
.menu ul li {float:left; margin-right:1px; position:relative;}
.menu ul li ul {display: none;}
/* specific to non IE browsers */
.menu ul li:hover a {color:#fff; background:#36f;}
.menu ul li:hover ul {display:block; position:absolute; top:21px; left:0; width:105px;}
.menu ul li:hover ul li a.hide {background:#6a3; color:#fff;}
.menu ul li:hover ul li:hover a.hide {background:#6fc; color:#000;}
.menu ul li:hover ul li ul {display: none;}
.menu ul li:hover ul li a {display:block; background:#ddd; color:#000;}
.menu ul li:hover ul li a:hover {background:#6fc; color:#000;}
.menu ul li:hover ul li:hover ul {display:block; position:absolute; left:105px; top:0;}
.menu ul li:hover ul li:hover ul.left {left:-105px;}
</style>
<!--[if lte IE 6]>
<style type="text/css">
.menu ul li a.hide, .menu ul li a:visited.hide {display:none;}
.menu ul li a:hover ul li a.hide {display:none;}
.menu ul li a:hover {color:#fff; background:#36f;}
.menu ul li a:hover ul {display:block; position:absolute; top:21px; left:0; width:105px;}
.menu ul li a:hover ul li a.sub {background:#6a3; color:#fff;}
.menu ul li a:hover ul li a {display:block; background:#ddd; color:#000;}
.menu ul li a:hover ul li a ul {visibility:hidden;}
.menu ul li a:hover ul li a:hover {background:#6fc; color:#000;}
.menu ul li a:hover ul li a:hover ul {visibility:visible; position:absolute; left:105px; top:0; color:#000;}
.menu ul li a:hover ul li a:hover ul.left {left:-105px;}
</style>
<![endif]-->
</head>
<body>
<table width="70%">
<tr>
<td>1212</td>
</tr>
</table>
<div class="menu">
<ul>
<li><a class="hide" href="../menu/index.html">DEMOS</a>
<!--[if lte IE 6]>
<a href="../menu/index.html">DEMOS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../menu/zero_dollars.html" title="The zero dollar ads page">zero dollars</a></li>
<li><a href="../menu/embed.html" title="Wrapping text around images">wrapping text</a></li>
<li><a class="hide" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">HOVER/CLICK ></a>
<!--[if lte IE 6]>
<a class="sub" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">HOVER/CLICK >
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a href="../menu/shadow_boxing.html" title="Multi-position drop shadow">shadow boxing</a></li>
<li><a href="../menu/em_images.html" title="em size images compared">em sized images</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="index.html">MENUS</a>
<!--[if lte IE 6]>
<a href="index.html">MENUS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="spies.html" title="a coded list of spies">spies menu</a></li>
<li><a href="jigsaw.html" title="jigsaw links">jigsaw links</a></li>
<li><a href="circles.html" title="circular links">circular links</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../layouts/index.html">LAYOUTS</a>
<!--[if lte IE 6]>
<a href="../layouts/index.html">LAYOUTS
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../layouts/bodyfix.html" title="Cross browser fixed layout">Fixed 1</a></li>
<li><a href="../layouts/minimum.html" title="A simple minimum width layout">minimum width</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../boxes/index.html">BOXES</a>
<!--[if lte IE 6]>
<a href="../boxes/index.html">BOXES
<table><tr><td>
<![endif]-->
<ul>
<li><a href="spies.html" title="a coded list of spies">spies menu</a></li>
<li><a href="circles.html" title="circular links">circular links</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../mozilla/index.html">MOZILLA</a>
<!--[if lte IE 6]>
<a href="../mozilla/index.html">MOZILLA
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../mozilla/dropdown.html" title="A drop down menu">drop down menu</a></li>
<li><a href="../mozilla/shadow_text.html" title="Shadow text">shadow text</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../ie/index.html">EXPLORER</a>
<!--[if lte IE 6]>
<a href="../ie/index.html">EXPLORER
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../ie/exampleone.html" title="Example one">example one</a></li>
<li><a href="../ie/exampletwo.html" title="Vertical align">vertical align</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
<li><a class="hide" href="../opacity/index.html">OPACITY</a>
<!--[if lte IE 6]>
<a href="../opacity/index.html">OPACITY
<table><tr><td>
<![endif]-->
<ul>
<li><a href="../opacity/colours.html" title="colour wheel">opaque colours</a></li>
<li><a class="hide" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">< HOVER/CLICK</a>
<!--[if lte IE 6]>
<a class="sub" href="../menu/hover_click.html" title="Hover/click with no active/focus borders">< HOVER/CLICK
<table><tr><td>
<![endif]-->
<ul class="left">
<li><a href="../menu/form.html" title="Styling forms">styled form</a></li>
<li><a href="../menu/hover_click.html" title="Hover/click with no active/focus borders">hover/click</a></li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
</ul>
<!--[if lte IE 6]>
</td></tr></table>
</a>
<![endif]-->
</li>
</ul>
</div>
</body>
</html>