public void save() {
		SortedMap<String,String> sortedKeys = new TreeMap<String,String>(keys);
		try {
			BufferedWriter output = new BufferedWriter(new FileWriter(fileName));
			try {
				for (String key : sortedKeys.keySet())
					output.write(key.toLowerCase() + "=" + sortedKeys.get(key) + newLine);
			} catch (IOException e) {
				e.printStackTrace();
			}
			output.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}