<div style="position:absolute; width:100%; height:100%; z-index:-1; left:0; top:0;">
<img src="Images/logo.png" style="left:0; top:0; height:100%;width:100%">
</div> // 设置为最底层（通用）<div id="formbackground" style="position:absolute; z-index:-1;"><img src="10.jpg" height="100%" width="100%"/></div>
<script type="text/javascript">$(function(){ $(‘#formbackground‘).height($(window).height()); $(‘#formbackground‘).width($(window).width());});</script>// jquery书写方式原文：http://www.cnblogs.com/zhang102137/p/6125216.html