protected Vector<Integer> fillChoices(Room R)
	{
		final Vector<Integer> choices=new Vector<Integer>();
		for(int d=Directions.NUM_DIRECTIONS()-1;d>=0;d--)
		{
			final Room room=R.getRoomInDir(d);
			final Exit exit=R.getExitInDir(d);
			final Exit opExit=R.getReverseExit(d);
			if((room!=null)
			&&((room.domainType()&Room.INDOORS)==0)
			&&(room.domainType()!=Room.DOMAIN_OUTDOORS_AIR)
			&&((exit!=null)&&(exit.isOpen()))
			&&(opExit!=null)&&(opExit.isOpen()))
				choices.addElement(Integer.valueOf(d));
		}
		return choices;
	}