可扩展性的层导航菜单问题 ，

Question

我在做一个可扩展的导航菜单，菜单在页面的正上方，菜单结构如下： 
          product menu
                 categoriy1 
                         subcategoriy1
                         subcategoriy2
                         subcategoriy3 
                 categoriy2
                         subcategoriy1
                         subcategoriy2
                         subcategoriy3   
当鼠标点击"product menu" 只出现
             categoriy1 
             categoriy2 
当鼠标点击或者移动到  categoriy1 的时候，要显示下一层子菜单 如：           product menu
                 categoriy1 
                         subcategoriy1
                         subcategoriy2
                         subcategoriy3 
                 categoriy2 就好比我们用windows 一样， 
有没有高手帮忙一下？ 谢谢  
             
                            

Answer 1

呵呵, 这个问题以前弄过, 很简单<tag>
 <a></a>
 <tag>
  <a></a>
  <tag>
   <a></a>
  </tag>
 </tag>
</tag>上前的结构就可以用几行代码实现N层的事件....

Answer 2

菜单： <ul class="menu"> 
             <li>Home</li> 
             <li>Contact us</li>
             <li>Membership</li> 
             <li>Sit map</a></li>
             <li>Shopping Cart</li>
        </ul> 
<div   id="mnul" onMouseOut="in_out(mnu1,0);">    
<span   id="cat";  onMouseOver="in_out(mnu1,1)"    >
<p>Catalogue</p></a></span>    
<div    id="mnu1"    style="position:    absolute;  left:-2;top:14;width:117;height:80;z-index:1;visibility:hidden">    
<a    id="link"    href=" products.php">Tops </a><br />
<a    id="link"    href="bottoms.php "> Bottoms</a><br /> 
<a    id="link"    href="contact.php ">Bags </a><br />  
<a    id="link"    href="register.php ">Shoes </a><br />   
<a    id="link"    href="sitemap.php "> Accessories </a> <br />
<a    id="link"    href="clearance.php">Clearance </a><br /> 
</div>    这个只能显示出 ：
                   
            product menu
                categoriy1 
                categoriy2
                categoriy3 
无法再进一步显示子菜单 ：  product menu
                                    categoriy1 
                                            subcategoriy1
                                            subcategoriy2
                                             subcategoriy3 

Answer 3

谢谢btbtd， 能不能再讲清楚一点，如何使用你那段代码？ sorry我是新手，不是很明白，谢谢谢谢谢谢～～～～