问题提出我用dw做了一个下拉菜单，但是碰到form的列表项就跑到下面去了，请帮忙解决，请看问题图示如下
解决问题由于层与下拉框之间的优先级是下拉框 %26gt; 层，因此在显示的时候，会因为优先级的次序而会出现如上问题。（假如几个元素都是层的话，我们可以通过层的 z-index 属性来设置）解决办法就是给层中放一个优先级比下拉框更高的元素（iframe），从而解决此问题！具体解决代码如下
%26lt;div id="menu" style="position:absolute; visibility:hidden; top:20px; left:20px; width:100px; height:200px; background-color:#6699cc;"%26gt;
%26lt;table%26gt;
%26lt;tr%26gt;%26lt;td%26gt;item 1%26lt;/td%26gt;%26lt;/tr%26gt;
%26lt;tr%26gt;%26lt;td%26gt;item 2%26lt;/td%26gt;%26lt;/tr%26gt;
%26lt;tr%26gt;%26lt;td%26gt;item 3%26lt;/td%26gt;%26lt;/tr%26gt;
%26lt;tr%26gt;%26lt;td%26gt;item 4%26lt;/td%26gt;%26lt;/tr%26gt;
%26lt;tr%26gt;%26lt;td%26gt;item 5%26lt;/td%26gt;%26lt;/tr%26gt;
%26lt;/table%26gt;
%26lt;iframe src="javascript:false" style="position:absolute; visibility:inherit; top:0px; left:0px; width:100px; height:200px; z-index:-1; filter='progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)';"%26gt;%26lt;/iframe%26gt;
%26lt;/div%26gt;
%26lt;a href="#" onclick="document.getElementById('menu').style.visibility='visible'"%26gt;menu%26lt;/a%26gt;
%26lt;form%26gt;
%26lt;select%26gt;%26lt;option%26gt;A form selection list%26lt;/option%26gt;%26lt;/select%26gt;
%26lt;/form%26gt;