纯CSS+DIV对联

CSS代码为：
.r1{width:80px;height:80px;background:red;float:right;  
     position:fixed !important; top/**/:200px;  
     position:absolute; z-index:300; top:expression(offsetParent.scrollTop+200);right:20px;}
.r2{width:80px;height:80px;background:red;float:right;  
     position:fixed !important; top/**/:300px;  
     position:absolute; z-index:400; top:expression(offsetParent.scrollTop+300);right:20px;}
.l1{width:80px;height:80px;background:red;float:right;  
     position:fixed !important; top/**/:200px;  
     position:absolute; z-index:300; top:expression(offsetParent.scrollTop+200);left:20px;}
.l2{width:80px;height:80px;background:red;float:right;  
     position:fixed !important; top/**/:300px;  
     position:absolute; z-index:400; top:expression(offsetParent.scrollTop+300);left:20px;}

页面代码为：
<div class="r1"><a href="/d/adclick.php?id=11&url=http://www.25idc.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div> 
<div class="r2"><a href="/d/adclick.php?id=11&url=http://www.25idc.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div> 
<div class="l1"><a href="/d/adclick.php?id=11&url=http://www.25idc.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div> 
<div class="l2"><a href="/d/adclick.php?id=11&url=http://www.25idc.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div> 

出处：源码网