private void OnShutdown(object sender, System.EventArgs e)
        {
            if (_form != null)
            {
                _form.Dispose();
                _form = null;
            }

            Application.SlideShowBegin -= OnSlideShowBegin;
            Application.SlideShowEnd -= OnSlideShowEnd;
            Application.SlideShowNextSlide -= OnNextSlide;
        }
        private void OnStartup(object sender, System.EventArgs e)
        {
            _form = new RemoteControlForm(this);

            Application.SlideShowBegin += OnSlideShowBegin;
            Application.SlideShowEnd += OnSlideShowEnd;
            Application.SlideShowNextSlide += OnNextSlide;
        }