拉伸铺满整个页面

CSS样式：

<style type="text/css" >

            body
            {
                height:100%;
                width:100%;
                margin:0;
            }
           
            .cover
            {
                width:100%;
                height:100%;
                position:fixed;
                z-index:-10;
            }
           
            .cover img
            {
                width:100%;
                height:100%;
                border:0;
            }

 </style>

 

HTML代码：

<div class="cover"><img  src="images/bg.jpg" /></div>