body {
	margin: 0px;
	padding: 0px;
	text-align: center;
	background: #9e9e9e url(../img/bg.jpg) repeat-x;
}
.contenedor {
	width: 1000px;
	margin-left: -500px;
	height: 580px;
	position: absolute;
	left:50%;
	background: url(../img/construccion.jpg) no-repeat;
}