private void OnSearch(object sender, EventArgs e)
        {
            _totalPages         = 0;
            _parsedPages        = 0;
            _form.PageCount     = 0;
            _form.ResultCount   = 0;
            _form.CanSearchNext = false;
            object state = _form.BeginSearching();

            try
            {
                Layout layout = _form.GetLayout();
                if (new IsEmptyString(layout.SearchText))
                {
                    return;
                }
                WebPageInfo pageInfo = new AvitoPage(_settings, new AvitoPageRequest(_settings, layout.SearchText)).Info();
                if (pageInfo.PageCount == 0)
                {
                    return;
                }

                _form.PageCount = _totalPages = pageInfo.PageCount;
                for (int i = 1; i <= layout.PagesPerSet; i++)
                {
                    _parsedPages++;
                    if (_parsedPages > _totalPages)
                    {
                        return;
                    }
                    List <WebSearchResult> newResults = SearchOnPage(i, layout);
                    for (int j = 0; j < newResults.Count; j++)
                    {
                        _form.ResultCount++;
                        _form.AddResultEntry(newResults[j]);
                    }
                }
            }
            finally
            {
                _form.EndSearching(state);
                _form.CanSearchNext = _parsedPages < _totalPages;
                SortBy();
            }
        }