title: How to add action to buttons in Alert in Swift
body: <p>I am beginner level programmer. I am trying to add action to buttons on Alert, but it doesn't work. I just want to test if the alert button choice can change the text in label, but it doesn't work. Of course I can see the alert and buttons well, but nothing happens after clicking the button. </p>
  
  <pre><code>@IBOutlet var statusLabelAlert : UILabel
  
  var alertTest = UIAlertView()
  
  @IBAction func alertButton(sender : AnyObject) {
  
      alertTest.message = "Select one!"
      alertTest.addButtonWithTitle("1st")
      alertTest.addButtonWithTitle("2nd")
      alertTest.addButtonWithTitle("3rd")
      alertTest.title = "Test Alert"
      alertTest.show()
  
  }
  func alertView(alertView: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){
      switch buttonIndex{
      case 0:
          statusLabelAlert.text = "1st"
      case 1:
          statusLabelAlert.text = "2nd"
      case 2:
          statusLabelAlert.text = "3rd"
      default:
          statusLabelAlert.text = "error"
      }
  
  }
  </code></pre>