#contenedor
{
	margin: 0 auto 0 auto;
	margin-left: -375px;
	margin-top: -300px;
	position: absolute;
	width:750px;
	height:600px;
	top: 50%;
	left: 50%;
	z-index:1;
	overflow: hidden;
}

#fondo
{
	width:750px;
	height:600px;
	position: absolute;
	left: 0px;
	top: 0px;
	z-index: 2;
	background-color:#FFFFFF;
	overflow: hidden;
}