private void enter_Click(object sender, RoutedEventArgs e)
 {
     //передача в чат сообщения
     try
     {
         var chatClient = new ChatServiceClient();
         var soobsh     = string.Format("{0} - {1}\n{2}\n", DateTime.Now, login.Text, vvod.Text);
         chatClient.Chat((string)((ListBoxItem)names.Items[names.SelectedIndex]).Content, soobsh);
         vvod.Text     = "";
         os.Visibility = Visibility.Hidden;
     }
     catch
     {
         os.Visibility = Visibility.Visible;
     }
 }