public override void Update(GameTime gameTime)
        {
            // mouse state is given to mouse
            tictactoeMouse = Mouse.GetState();

            // mouse collision algorithim
            mouseCollision.X = tictactoeMouse.X;
            mouseCollision.Y = tictactoeMouse.Y;

            // collision for mouse to change state
            if (buttonContinueRect.Intersects(mouseCollision))
            {
                buttonIsHit    = true;
                continuebutton = tictactoeButtonState.hit;
                if (ButtonState.Pressed == tictactoeMouse.LeftButton)
                {
                    ScreenManager.Instance.AddScreen(new TicTacToeGameScreen());
                }
            }

            if ((Keyboard.GetState(PlayerIndex.One).IsKeyDown(Keys.Enter)))
            {
                ScreenManager.Instance.AddScreen(new TicTacToeGameScreen());
            }

            if (!buttonContinueRect.Intersects(mouseCollision))
            {
                buttonIsHit    = true;
                continuebutton = tictactoeButtonState.free;
            }
        }
        public TicTacToeTitleScreen()
        {
            volumeLevel        = 1.0f;
            tictactoeMouse     = new MouseState();
            mouseCollision     = new Rectangle(0, 0, 24, 24);
            buttonContinueRect = new Rectangle(750, 500, 256, 128);

            continuebutton = tictactoeButtonState.free;
        }