private void NotifyArrival_Click(object sender, RoutedEventArgs e)
        {
            ArrivalAndDeparture a = (ArrivalAndDeparture)(((FrameworkElement)sender).DataContext);

            this.popup = new Popup();

            NotifyPopup notifyPopup = new NotifyPopup();
            notifyPopup.Notify_Completed += delegate(object o, NotifyEventArgs args) 
            {
                if (args.okSelected == true)
                {
                    this.viewModel.SubscribeToToastNotification(a.stopId, a.tripId, args.minutes);
                }

                // This is how we track if the popup is visible
                Dispatcher.BeginInvoke(() => { this.popup.IsOpen = false; });
            };

            this.popup.Child = notifyPopup; 
            this.popup.IsOpen = true;
        }