UIAlert

var alert=UIAlertController(title: "Hey there?", message: "Are you sure?", preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { (action) -> Void in
    self.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert, animated: true, completion: nil)