private void radUnread_Checked(object sender, RoutedEventArgs e)
        {
            if (user == null)
                return;

            NotifHelper client = new NotifHelper();
            if (radUnread.IsChecked == true)
            {
                lstMsg.ItemsSource = client.GetUnreadMessages(user, user.UserID);
            }
            else
            {
                lstMsg.ItemsSource = client.GetAllMessages(user, user.UserID);
            }
            client.Close();
        }