     let ButtonFontSize: CGFloat = 17
     var animator: UIDynamicAnimator?
     var presentedAnimation: Bool = true
-    var keyboardHeight: CGFloat = 0
     
     var message: String?
     

            if let frame = notification.userInfo?[UIKeyboardFrameEndUserInfoKey]?.CGRectValue() {
                let rect = window.convertRect(frame, toView: view)
                
                keyboardHeight = view.bounds.size.height - rect.origin.y
            }
        }
    }
    
    func keyboardDidShow(notification: NSNotification) {
        backgroundViewBottomSpaceConstraint.constant = keyboardHeight
    }
}


        modalTransitionStyle = .CrossDissolve
        transitioningDelegate = self
        
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
    }
    
    public override func viewDidLoad() {
