void Report_StartReport(object sender, EventArgs e)
{
    Page1.Visible = ((FastReport.Data.TableDataSource)Report.GetDataSource("StockRep")).Table.Select("rowid <> ''").Length > 0;
    Page2.Visible = ((FastReport.Data.TableDataSource)Report.GetDataSource("StockRep3")).Table.Select("rowid <> ''").Length > 0;
}