     
     override func viewDidDisappear(animated: Bool) {
         super.viewDidDisappear(animated)
-        view.alpha = 1.0
-        activityIndicator.hidden = true
     }
 
     var sharedContext: NSManagedObjectContext {

                
                LoginProvider.Email(user).login(self)
            }else{
                view.alpha = 1.0
                sender.enabled = false
                activityIndicator.hidden = true
                activityIndicator.stopAnimating()
                showAlert(.unCompleteField)
            }
        }

    @IBOutlet weak var emailText: UITextField!
    @IBOutlet weak var passwordText: UITextField!
    

    @IBOutlet weak var singInstackView: UIStackView!
    
    override func viewDidLoad() {
        super.viewDidLoad()

        let backgroundImage = UIImageView(frame: UIScreen.mainScreen().bounds)
        backgroundImage.image = UIImage(named: "background")
        view.insertSubview(backgroundImage, atIndex: 0)
