Play again button doesn't work
<p>When I press the play again button it doesn't work. I just have this code involving the play again button. What should I add here? How can I add a function to <code>playAgain</code> button?  Here is my code:</p>

<pre><code>  let playAgain: UIButton = UIButton(frame: CGRectMake(-10, 400, 400, 150))
   playAgain.setTitle("Play Again", forState: UIControlState.Normal)
   playAgain.titleLabel!.font = UIFont(name: "Helvetica", size: 50)
     playAgain.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
            playAgain.tag = 1
            self.view!.addSubview(playAgain)
</code></pre>