private static void loadGuiProperties() {
        if (properties == null) {
            properties = new Properties();
        }
        try {
            InputStream props = App.class.getResourceAsStream(
                    "/net/sourceforge/jnipp/gui/resources/gui.properties");
            props = new BufferedInputStream(props);
            properties.load(props);
            props.close();
        } catch (IOException e) {
            //loading properties file failed
            e.printStackTrace();
        }
    }