private void loadGrid_Report(DateTime startDate, DateTime endDate)
        {
            SaleInvoice repository = new SaleInvoice();
            var         result     = repository.getProductByTime(startDate, endDate);

            if (result.Count > 0)
            {
                gridProduct.DataSource = result;
                gridProduct.DataBind();
                gridProduct.Visible = true;
            }
            else
            {
                gridProduct.Visible = false;
                this.ShowWarningNotification("No data found");
            }
        }