让footer始终位于页面的最底部不随滚动而滚动

<div class="container">
<div cass="header"></div>
<div class="body"></div>
<div class="footer"></div>
</div>

.container{position:relative;width:100%;min-height:100%;}
.body{padding-bottom:50px;}
.footer{height:50px;position:absolute;bottom:0px;left:0px;}

.container{position:relative;width:100%;min-height:100%;}
.body{padding-bottom:50px;}
.footer{height:50px;position:fixed;bottom:0px;left:0px;}