html, body {
	height: 100%;
}

#centeredcontent {
	width: 960px;
	height: 720px;
	text-align: center;
	border: 1px solid #000;
	background-image: url(../_imgs/sabron.gif);
	color: #fff;
	position: absolute;
	left: 50%;
	top: 50%;
	margin-left: -480px; 
	/* Half the width of the DIV tag which is 50 pixels */
	margin-top: -360px; 
	/* Half the height of the DIV tag which is also 50 pixels */
}