public static String getKeysFromValue(HashMap<Integer, String> hm,
			String value) {
		Set<?> s = hm.entrySet();
		// Move next key and value of HashMap by iterator
		Iterator<?> it = s.iterator();
		while (it.hasNext()) {
			// key=value separator this by Map.Entry to get key and value
			Map.Entry m = (Map.Entry) it.next();
			if (m.getValue().equals(value))
				return m.getKey() + "";
		}
		System.err.println("Error, can't find the data in Hashmap!");
		return null;
	}