public LinkedList<Theater> getAllTheaters(int zone){
		LinkedList<Theater> result;



		switch(zone){
		case 1: 
			result = TheaterCatalog.getAllTheaters(zone);
			if(result == null)
				result = loadTheatersFromDisk(NorthTheatersFile);

			TheaterCatalog.addTheater(result);
			return result;
		case 2:
			result = TheaterCatalog.getAllTheaters(zone);
			if(result == null)
				result = loadTheatersFromDisk(CenterTheatersFile);

				TheaterCatalog.addTheater(result);
				
			return result;
		case 3: 
			result = TheaterCatalog.getAllTheaters(zone);
			if(result == null)
				result = loadTheatersFromDisk(SouthTheatersFile);

			TheaterCatalog.addTheater(result);
			return result;
		default: return null; 
		}

	}