js控制右下角停留效果，最简便，全部浏览器测试通过

    /*右下角广告*/
    #pop{width:310px;position:fixed;right:17px;overflow:hidden;height:246px;}/**/
    #pop img{margin:0;padding:0;border:0;display:block;}
    #pop .close{width:43px;height:16px;display:block;position:absolute;right:8px;top:2px;overflow:hidden;background:url(http://image.sxmtxs.com/webimg/43_16.jpg);cursor:pointer;}




<div id="pop" style="bottom:-250px;">
    <img src="http://image.sxmtxs.com/webimg/298_224_1.jpg" width="310" height="250" />
    <div class="close" onmousedown="hidePop();"></div>
</div>
<script type="text/javascript">
    //弹出窗口的div
    var pop=document.getElementById("pop");var bott;
    //弹出窗口的高度，包括边框
    var popHeight=250;
    var flag=true;
    function ie6Int(){
        pop.style.height="0px";pop.style.position="absolute";
        pop.style.display="block";
        pop.style.bottom="";pop.style.right="17px";
        var beginTop=pop.style.top.replace("px","");
        var scroll=document.documentElement.scrollHeight;
        pop.style.top=parseInt(document.documentElement.clientHeight,10)+document.documentElement.scrollTop+"px";
        window.onscroll=function(){
            ///当滚动条到最底时，不再继续滚动
            if(parseInt(document.documentElement.clientHeight,10)+document.documentElement.scrollTop>=scroll) return;
            var currScroll=parseInt(document.documentElement.clientHeight,10)-popHeight;
            pop.style.top=document.documentElement.scrollTop+currScroll+"px";