NSTimer in Swift?

 import Cocoa

class ViewController: NSViewController {

    override func viewDidLoad() {

        super.viewDidLoad()

var timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("increment"), userInfo: nil, repeats: true)        // Do any additional setup after loading the view.

    }

    override var representedObject: AnyObject? {

        didSet {

        // Update the view, if already loaded.

        }

    }

    func increment(){

    var i = 0

        i++

        tf.stringValue = "\(i).Mal"

    }

    @IBOutlet weak var tf: NSTextField!

}