该代码在IE和FF下测试通过：
代码
<html>
<head>
<script language="JavaScript" type="text/javascript">
function $(obj){
return document.getElementById(obj);
}
function pop(obj){
var h = parseInt(currentStyle($("popDiv")).height);
$("popDiv").style.height = (h + obj) + "px";
if(parseInt($("popDiv").style.height) < 2){
window.clearInterval(timer);
$("popDiv").style.display = "none";
}
if(parseInt($("popDiv").style.height) >= 200){
window.clearInterval(timer);
}
}
function currentStyle(element) {
return element.currentStyle || document.defaultView.getComputedStyle(element, null);
}
var timer;
function runtimer(obj){
timer = window.setInterval(function(){pop(obj)},10);
}
window.onload = function(){
runtimer(2);
}
</script>
</head>
<body >
<div style="position:absolute;right:0;bottom:0;height:0px;200px;border:1px solid red;" id="popDiv">
<a href="javascript:runtimer(-2);">×</a>
</div>
</body>
</html>
<head>
<script language="JavaScript" type="text/javascript">
function $(obj){
return document.getElementById(obj);
}
function pop(obj){
var h = parseInt(currentStyle($("popDiv")).height);
$("popDiv").style.height = (h + obj) + "px";
if(parseInt($("popDiv").style.height) < 2){
window.clearInterval(timer);
$("popDiv").style.display = "none";
}
if(parseInt($("popDiv").style.height) >= 200){
window.clearInterval(timer);
}
}
function currentStyle(element) {
return element.currentStyle || document.defaultView.getComputedStyle(element, null);
}
var timer;
function runtimer(obj){
timer = window.setInterval(function(){pop(obj)},10);
}
window.onload = function(){
runtimer(2);
}
</script>
</head>
<body >
<div style="position:absolute;right:0;bottom:0;height:0px;200px;border:1px solid red;" id="popDiv">
<a href="javascript:runtimer(-2);">×</a>
</div>
</body>
</html>
注意:在IE下获取控件的当前css要用currentStyle，而不能用style(该属性获取元素内嵌的样式，在该例子中明显不合适)，而在FF下要通过document.defaultView.getComputedStyle(element, null);获得当前css.