测了一下，还可以，在IE6、IE7、FIREOFX等都没有问题！ 窗口缩小时也没有问题！
<script language="JavaScript" type="text/javascript">
function test(){
var infoHeight = document.getElementById("info").scrollHeight;
var bottomHeight = document.getElementById("bottom").scrollHeight;
var allHeight = document.documentElement.clientHeight;
var bottom = document.getElementById("bottom");
if((infoHeight + bottomHeight) < allHeight){
bottom.style.position = "absolute";
bottom.style.bottom = "0";
}else{
bottom.style.position = "";
bottom.style.bottom = "";
}
setTimeout(function(){test();},10);
}
test();
</script>