div.pantalla
{
 position: absolute;

 left: 10px;
 top: 10px;

 background-image: url('../img/fondo1.png');
 background-repeat: no-repeat;
 width: 770px;
 height:540px;
}div.pantalla2 {
	position: absolute;
	left: 10px;
	top: 10px;
	background-image: url(../img/fondo2.png);
	background-repeat: no-repeat;
	width: 770px;
	height:540px;
}
div.pantalla3 {
	position: absolute;
	left: 10px;
	top: 10px;
	/* [disabled]background-image: url(../img/fondo2.png); */
	/* [disabled]background-repeat: no-repeat; */
	width: 770px;
	height:540px;
}