<div style="width:360px;height:200px;border:red 1px solid; margin-left:100px; margin-top:300px; position:relative; ">
<img style="position:absolute;left:0px;top:0px;width:100%;height:100%;z-Index:-1; border:1px solid blue" src="包囊.png" />背景图片的验证
</div>
原文：http://www.cnblogs.com/rzm2wxm/p/7307879.html