private void mnu_howToPlay_Click(object sender, RoutedEventArgs e)
        {
            // Event handler for when the user clicks How to Play
            // from the Help menu
            // Opens a new HowToPlayWindow
            InstructionWindow in_window = new InstructionWindow();

            in_window.Show();
            this.Close();
        }
        private void btn_howToPlay_Click(object sender, RoutedEventArgs e)
        {
            // Event handler for when the user clicks the How to Play button
            // Opens a new HowToPlayWindow



            InstructionWindow in_window = new InstructionWindow();

            in_window.Show();
            //this.Close();
        }