private void Disconnect_Click(object sender, RoutedEventArgs e)
 {
     try
     {
         mServiceA.DeregisterClient(this);
     }
     catch (FaultException fEx)
     {
         textBox.AppendText("Fault exception was thrown: " +
                            fEx.Message +
                            " " + fEx.Reason +
                            " " +
                            "SOAP Code: " + fEx.Code +
                            "\n");
     }
     catch (Exception ex)
     {
         textBox.AppendText("Exception was thrown: " + ex.Message);
     }
 }