private async void CallButton_Click(object sender, RoutedEventArgs e)
 {
     if (SharePage.SendTo == null)
     {
         MessageDialog mb = new MessageDialog("Please select a device to send to.");
         mb.ShowAsync();
         return;
     }
     progrBar.Visibility = Visibility.Visible;
     Command t = new Command();
     t.Address = txtAddress.Text;
     await App.MobileService.GetTable<Command>().InsertAsync(t);
     progrBar.Visibility = Visibility.Collapsed;
 }
        private async void TextButton_Click(object sender, RoutedEventArgs e)
        {
            if (SharePage.SendTo == null)
            {
                MessageDialog mb = new MessageDialog("Please select a device to send to.");
                mb.ShowAsync();
                return;
            }
            if (txtTextContent.Visibility == Visibility.Collapsed)
            {
                txtTextContent.Visibility = Visibility.Visible;
            }
            else
            {
                progrBar.Visibility = Visibility.Visible;
                Command t = new Command();
                t.Text = txtTextContent.Text;
                t.Number = txtNumber.Text;
                await App.MobileService.GetTable<Command>().InsertAsync(t);

                txtTextContent.Visibility = Visibility.Collapsed;
                progrBar.Visibility = Visibility.Collapsed;
            }
        }