body{height:100%;overflow:hidden;position:relative}
.fixed{position:absolute;top:10px;left:10px}
.container{height:100%;overflow:auto}

<script language="javascript" type="text/javascript">
window.onload=function(){
if(!window.XMLHttpRequest){//ie6
var n=0;  //top值
var obj=document.getElementById("topbox"); //position:fixed对象
window.onscroll=function(){obj.style.top=(document.body.scrollTop||document.documentElement.scrollTop)+n+'px';}
window.onresize=function(){obj.style.top=(document.body.scrollTop||document.documentElement.scrollTop)+n+'px';}
}
}
</script>