/// <summary>
 /// When the user cancels the main menu, ask if they want to exit the sample.
 /// </summary>
 protected override void OnCancel(PlayerIndex playerIndex)
 {
     const string message = "Are You Sure You Want To Quit?";
     MessageBoxScreen confirmExitMessageBox = new MessageBoxScreen(message);
     confirmExitMessageBox.Accepted += ConfirmExitMessageBoxAccepted;
     ScreenManager.AddScreen(confirmExitMessageBox, playerIndex);
 }
        /// <summary>
        /// Event handler for when the Quit Game menu entry is selected.
        /// </summary>
        void QuitGameMenuEntrySelected(object sender, PlayerIndexEventArgs e)
        {
            const string message = "Are you sure you want to quit the game?";

            MessageBoxScreen confirmQuitMessageBox = new MessageBoxScreen(message);

            confirmQuitMessageBox.Accepted += ConfirmQuitMessageBoxAccepted;

            ScreenManager.AddScreen(confirmQuitMessageBox, ControllingPlayer);
        }