.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;} 

div class="r1">a  />/a>/div>   
div class="r2">a  />/a>/div>   
div class="l1">a  />/a>/div>   
div class="l2">a  />/a>/div>