大家看看，我想让它速度慢点！

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
#winpop
{
width: 200px;
height: 0px;
position: absolute;
right: 0;
bottom: 0px;
border: 1px solid #99999;
margin: 0px;
padding: 1px;
overflow: hidden;
background: #fff;
display: none;
}
div.title
{
width: 100%;
height: 20px;
line-height: 20px;
background: #290052;
font-weight: bold;
text-align: center;
font-size: 12px;
color: #fff;
}
div.content
{
width: 100%;
height: 80px;
line-height: 80px;
font-weight: bold;
font-size: 12px;
color: #ff0000;
text-decoration: underline;
text-align: center;
border: 1px solid #290052;
}
.close
{
position: absolute;
right: 4px;
top: -1px;
color: #fff;
cursor: pointer;
}
#glide
{
background: yellow;
border: 1px solid blue;
display: none;
}
</style>

<script language="javascript" type="text/javascript">
var MsgPop;
var popH;
var oDiv;
var oDivW;
var oDivH;
window.onload = function () {
MsgPop = document.getElementById("winpop");
MsgPop.style.height = "0px";

tips_pop();

/* setTimeout("tips_pop()", 5000);*/
setInterval("tips_pop()", 5000);
}
function tips_pop() {
popH = parseInt(MsgPop.style.height);
if (popH == 0) {
MsgPop.style.display = "block";
show =setInterval("changeH('up')", 2);
}
else {
hide = setInterval("changeH('down')", 2);
}
}
function changeH(str) {
popH = parseInt(MsgPop.style.height);
if (str=="up") {
if (popH <= 100) {
MsgPop.style.height = (popH + 4).toString() + "px";
}
else {
clearInterval(show);
}
}
if (str == "down") {
if (popH >= 4) {
MsgPop.style.height = (popH -4).toString() + "px";
}
else {
clearInterval(hide);
MsgPop.style.display = "none";
}
}
}
</script>

</head>
<body>
<div id="winpop">
<div class="title">
短消息<span class="close" onclick="tips_pop()">X</span>
</div>
<div class="content">
未读消息(3)</div>
</div>
</body>
</html>


以上是在右下角弹出的消息框，每隔一段时间就会弹一次，我觉得他出现和消失的速度太快了，我想让他慢慢的出来，退出或点关闭的时候在慢慢的消失。大家帮忙改改吧！