<head>
<style>
#myDiv {
width:200px;
height:150px;
border-radius:2px;
box-shadow:0px 0px 0px 2px #aaa;
margin-left: -9999px;
}
</style>
</head>
<body>
<input type="button" value="click" onclick="show()">
<div id="myDiv"></div>
<script type="text/javascript">
function show() {
var obj = document.getElementById("myDiv");
obj.style.margin = 0;
var normalH = 150;
var h = 0;
var timer = setInterval(function () {
h += 1;
obj.style.height = h + "px";
if (h >= normalH) clearInterval(timer);
}, 1)
}
</script>
</body>