public static String checkKeys(final String keyName, final String[] keyNames) {

		String result = null;

		if (keyNames != null && keyNames.length > 0 && keyName != null) {
			for (int i = 0; i < keyNames.length; i++) {
				if (keyName == keyNames[i]) {
					result = keyNames[i];
					break;
				}
			}
			if (result == null) {
				result = "error";
			}
		}
		return result;
	}