private async void AddUser()
        {
            try
            {
                user = await MobileService2.LoginAsync(MobileServiceAuthenticationProvider.MicrosoftAccount, "leafhomecontrol.azurewebsites.net");

                AccountsViewModel.AddUser(user.UserId, _homesViewModel.SelectedHome.Id);
            }
            catch (InvalidOperationException ex)
            {
            }
        }
        private async void AddGuest_bt_Click(object sender, RoutedEventArgs e)
        {
            string newUser = await ScanAsync();

            AccountsViewModel.AddUser(newUser, _homesViewModel.SelectedHome.HomeId);
        }