[原创] 纯css控制两边漂浮

修改自codepub.com，修正IE7下javascript报错的问题。

CSS代码为：

 1.r1{}{
 2     width:80px;height:80px;background:red;float:right;   
 3     position:fixed !important; top/**//**/:200px;   
 4     position:absolute; z-index:300; right:20px;
 5}
 6.r2{}{width:80px;height:80px;background:red;float:right;   
 7     position:fixed !important; top/**//**/:300px;   
 8     position:absolute; z-index:400; right:20px;}
 9.l1{}{width:80px;height:80px;background:red;float:right;   
10     position:fixed !important; top/**//**/:200px;   
11     position:absolute; z-index:300; left:20px;}
12.l2{}{width:80px;height:80px;background:red;float:right;   
13     position:fixed !important; top/**//**/:300px;   
14     position:absolute; z-index:400; left:20px;}
15* html .r1, * html .l1 {}{ top:expression(offsetParent.scrollTop+200); }
16* html .r2, * html .l2 {}{ top:expression(offsetParent.scrollTop+300); }

页面代码为：

1<div class="r1"><a href="http://www.kilobug.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div>  
2<div class="r2"><a href="http://www.kilobug.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div>  
3<div class="l1"><a href="http://www.kilobug.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div>  
4<div class="l2"><a href="http://www.kilobug.com" target='_about'><img src="/js/pic/piao-l-1.gif" width="80" height="80" border="0" /></a></div>