<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<style>
#popup {
display: none;
position: absolute;
width: 300px;
margin: 0 -150px;
left: 50%;
top: 50px;
padding: 20px;
background: #fff;
box-shadow: 3px 3px 15px rgba(0,0,0,0.5);
}
</style>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
<script>
$(function() {
$('#order').click(function() {
$('#popup').show(400)
})
});
</script>
</head>
<body>
<form>
<input name="as1" /> <input id="order" type="button" value="Order" />
<div id="popup">
<input name="as2"/><br />
<input name="as3"/><br />
<input type="submit" value="GO" />
</div>
</form>
</body>
</html>