private void btnSend_Click(object sender, RoutedEventArgs e) { if (SelectedLine == null) { return; } SelectedLine.SendOutofDialogInstantMessage(Recipient, InstantMessage); string msgSender = string.Format("{0}@{1}", SelectedLine.SIPAccount.UserName, SelectedLine.SIPAccount.GetSIPHostPort(SelectedLine.TransportType)); Model.AddInstantMessage(msgSender, InstantMessage); InstantMessage = ""; }