public override void LoadContent()
        {
            pixel = game.Content.Load <Texture2D>("pixel");
            font  = game.Content.Load <SpriteFont>("font");

            Texture2D tick = game.Content.Load <Texture2D>("texture1");

            a = new Checkbox
            {
                boxTexture   = pixel,
                tickTexture  = tick,
                labelFont    = font,
                label        = "checkbox a",
                defaultColor = Color.White,
                disableColor = Color.DarkGray,
                hoverColor   = Color.LightGray,
                labelColor   = Color.White,
                tickColor    = Color.White,
                rect         = new Rectangle(180, 100, 30, 30),
                focused      = true
            }; a.LoadContent();
            base.LoadContent();
        }