if i''ve got my main class as Game.as and my user interface for the game as UI.as, what's the best way to reference the Game from the UI?.. i'm currently doing this.. (passing the game by reference)

package
{
    import UI;

    class Game extends Sprite
    {    
        private var ui:UI;
        public var version:String;

        public function Game()
        {    
                        version = "1.0";
        }

        public function init()
        {
           ui = new UI();
           ui.setup(this);
        }

    }
}


package
{
        class UI extends Sprite;
        private var _game:Game;

        public function UI(game:Game)
        {    
                _game = game;
        }

        public function setup()
        {
                // do stuff
                trace(_game.version);
        }
}