/* contenedor principal */
#main
{ width: 1007px;
  height: 688px;
}

.centrado {
	position: absolute; 
	left: 50%; 
	height: 688px;
	width: 1007px;
	margin-left: -504px;
}

/*
.centrado {
	position: absolute; 
	top: 50%; 
	left: 50%; 
	height: 688px;
	width: 1007px;
	margin-top: -344px;
	margin-left: -504px;
}
*/