//Edit rating of book or video.
        private void btnEditRating_Click(object sender, RoutedEventArgs e)
        {
            string[] keys = (sender as Button).Tag.ToString().Split(':');
            EngServRef.ServerData type = keys[0] == "Book"? EngServRef.ServerData.Book : EngServRef.ServerData.Video;
            EditRating            book = new EditRating(_proxy, Convert.ToInt32(keys[1]), Convert.ToInt32(keys[2]), Convert.ToInt32(keys[3]), type);

            book.ShowDialog();

            switch (type)
            {
            case EngServRef.ServerData.Video:
                btnVideos_Click(null, null);
                break;

            case EngServRef.ServerData.Book:
                btnBooks_Click(null, null);
                break;
            }
        }