JS+CSS实现侧边栏跟随浏览器滚动效果

CSS
/侧栏跟随/
#box{float:left; position:relative;width:250px;}.div1{width:250px;}.div2{position:fixed;_position:absolute;:0;z-index:250;}
如贵站的侧边栏宽度不是250px，请另行修改！
JS
//侧栏跟随
(function(){
var oDiv=document.getElementById("float");
var H=0,iE6;
var Y=oDiv;
while(Y){H+=Y.offsetTop;Y=Y.offsetParent};
iE6=window.ActiveXObject&&!window.XMLHttpRequest;
if(!iE6){
window.onscroll=function()
{
var s=document.body.scrollTop||document.documentElement.scrollTop;
if(s>H){oDiv.className="div1 div2";if(iE6){oDiv.style.=(s-H)+"px";}}
else{oDiv.className="div1";}
};
}
})();