void ScreenChange(object sender, ScreenChangeEventArgs scrChangeEvtArgs)
 {
     NewScreen = scrChangeEvtArgs.newScreen;
     ScreenStack.Push(NewScreen);
     if (scrChangeEvtArgs.currentScreen != null)
     {
         if (scrChangeEvtArgs.currentScreen is MainScreen)
         {
             (scrChangeEvtArgs.currentScreen as MainScreen).SceneMngr.GetCurrentScene().sound.Stop();
                 }
         scrChangeEvtArgs.currentScreen.UnloadContent();
     }
     CurrentScreen = NewScreen;
     CurrentScreen.LoadContent(Content);
 }