public synchronized static void writeAllUsers(ArrayList<User> users) {
		
		ArrayList<User> existing = DataReader.getUsers();
		if(!existing.equals(users)) {
			
		}
		
		File f = new File("users.txt");
		FileWriter fr = null;
		try {
			fr = new FileWriter(f);
			BufferedWriter br = new BufferedWriter(fr);
			String s = "";

			for (User e : users) {
				s += e.getUsername() + " " + e.getBalance();
				s += "\n";
			}
			br.write(s);
			br.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}