public String getUserInput(String prompt) {
		String inputLine = null;
		System.out.print(prompt + "  ");
		try {
			BufferedReader is = new BufferedReader(new InputStreamReader (System.in));
			inputLine = is.readLine();
			if (inputLine.length() == 0) return null;
		} catch (IOException e) {
			System.out.println("IOException: "+ e);
		}
		return inputLine;
		}