head{ background:#000000;}
body{
	background: #000 url(fondoe4.jpg) no-repeat top left;
}
#principal {
    position: absolute;
    top: 50%;
    left: 50%;
	margin-top: -175px;
    margin-left: -300px;
    width: 300px;
    height: 236px;
}


/*#contenido {
	position: absolute;
    top: 50%;
    left: 50%;
	margin-top: -120px;
    margin-left: -310px;
    width: 650px;
    height: 520px;
}*/