<div id="floatPanel"> <div class="ctrolPanel" style="right:20px;"> <a class="arrow" href="#"><img title="点击回到顶部" src="images/huidao.jpg" /></a> </div> </div>
#floatPanel .ctrolPanel{width:60px;;height:60px;position:fixed;right:25px;top:85%;overflow:hidden;z-index:10000;}
原文：http://www.cnblogs.com/shark1100913/p/6281462.html