private void createVideoWindow()
{
videoWindow = new second(this);
videoWindow.WindowStartupLocation = System.Windows.WindowStartupLocation.Manual;
videoWindow.Top = 10;
videoWindow.Left = 10;
videoWindow.Topmost = true;
videoWindow.Closing += new CancelEventHandler(this.OnWindowClosing);
}
public void OnWindowClosing(object sender, CancelEventArgs e)
{
this.videoWindow = null;
}