世纪中国红色二级横向滑动导航菜单（修改版）

世纪中国首页红色二级横向滑动式导航菜单，此菜单原本不兼容火狐，在火狐下乱掉，经过修改优化，已经完美兼容火狐。DIV UL LI 结构，完全符合标准，结构清晰，易修改。主导航与子导航的结构代码是分开的。

主导航结构如下：

<!--主导航开始-->
    <DIV id=mainmenu_top>
        <UL>
        <LI><A id=mm1 onmouseover=showM(this1); onmouseout=OnMouseLeft(); href="http://51xuediannao.com/" target=_parent>懒人建站</A> </LI>
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        <LI><A id=mm3 onmouseover=showM(this3); onmouseout=OnMouseLeft(); href="http://51xuediannao.com/js/ad/" target=_parent>JS广告代码</A> </LI>
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        <LI><A id=mm6 onmouseover=showM(this6); onmouseout=OnMouseLeft(); href="http://51xuediannao.com/jiqiao/css/" target=_parent>CSS技巧</A> </LI>
        <LI><A id=mm7 onmouseover=showM(this7); onmouseout=OnMouseLeft(); href="http://51xuediannao.com/JS/nav/" target=_parent>CSS导航菜单</A> </LI>
        <LI style="DISPLAY: none"><A id=mm8 onmouseover=showM(this8); onmouseout=OnMouseLeft(); href="http://51xuediannao.com/HTML+CSS/" target=_parent>HTML+CSS模板</A> </LI>
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    </DIV>