public static bool CheckIfNull(SendWindow mw)
 {
     if (String.IsNullOrEmpty(mw.destination.Text) || String.IsNullOrEmpty(mw.fee.Text) || String.IsNullOrEmpty(mw.money.Text))
     {
         MessageBox.Show("Can not be empty", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
         return(true);
     }
     else
     {
         return(false);
     }
 }
 private void Send_Click(object sender, RoutedEventArgs e)
 {
     sw = new SendWindow();
 }