private void btnYes_Click(object sender, RoutedEventArgs e)
 {
     dlgResult = MsgDlgRslt.RSLT_YES;
     Close();
 }
 private void btnCancel_Click(object sender, RoutedEventArgs e)
 {
     dlgResult = MsgDlgRslt.RSLT_CANCEL;
     Close();
 }