public List<String> getUserList(String service, String userType) {
		List<String> users = new Vector<String>();
		BufferedReader br = getFileReader();
		String currentLine, user, tmpService;
		StringTokenizer strTk;
		
		if(br == null) {
			System.err.println("Error opening file");
			System.exit(1);
		}
		
		try {
			//Read until the end of file
			while ((currentLine = br.readLine()) != null) {
				strTk = new StringTokenizer(currentLine);
				user = strTk.nextToken();

				//reads services for all users
				if (!strTk.nextElement().equals(userType)) {
					while (strTk.hasMoreTokens()) {
						tmpService = strTk.nextToken();
						if(tmpService.equals(service))
							users.add(user);
					}
				}

			}
			br.close();
		} catch (IOException e) {
			System.err.println("Error reading database file");
			e.printStackTrace();
		}

		return users;
	}