I am using these code

Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>hello</title>
<meta name="" content="">

<style type="text/css">
#container {
	margin:0 auto;
	background-color:orange;
	color:blue;
	padding:10px;
	width:300px;
	height:300px;
	font-size:24px;
	font-weight:bolder;
	vertical-align:central;
	text-align:center;
	}
</style>

</head>
<body>

<div id="container">I am in the center of this div horizontally and vertically.</div>

</body>
</html>
I want to display div in center of screen, (both horizontally and vertically).

Text in this div must also appear in vertically center.

Please help