private List<vw_DeliveryLine> GetSelectedVwLines()
        {
            List<vw_DeliveryLine> certificates = new List<vw_DeliveryLine>();
              List<vw_DeliveryLine> certificateLinks = new List<vw_DeliveryLine>();

              if (RadGridCertificate.SelectedItems.Count == 0) // no check boxes selected
            return certificateLinks;
              else
              {
            if (radGridCheckBoxSellectAllChecked) // sellect all check box selected
            {
              IQueryable<vw_DeliveryLine> data = GetData();
              certificates = data.Where(c => c.CertificateLink != null).Select(c => c).Distinct().ToList();

              // Check if files exists
              certificateLinks = certificates.Where(c => File.Exists(HttpContext.Current.Server.MapPath(c.CertificateLink))).ToList();
            }

            else // some check boxes selected
            {
              GridItemCollection gridItemCollection = RadGridCertificate.SelectedItems;
              foreach (GridDataItem data in gridItemCollection)
              {
            if (data.GetDataKeyValue("CertificateLink") != null)
            {
              vw_DeliveryLine line1 = new vw_DeliveryLine();
              line1.companyCode = data.GetDataKeyValue("companyCode").ToString();
              line1.DELDocId = Convert.ToInt32(data.GetDataKeyValue("DELDocId"));
              line1.DELDocNum = data.GetDataKeyValue("DELDocNum").ToString();
              line1.DELLineNum = Convert.ToInt32(data.GetDataKeyValue("DELLineNum").ToString());
              line1.batchId = Convert.ToInt32(data.GetDataKeyValue("batchId"));
              line1.HeatNumber = data.GetDataKeyValue("HeatNumber").ToString();
              line1.CertificateLink = data.GetDataKeyValue("CertificateLink").ToString();
              line1.customerReference = data.GetDataKeyValue("CustomerReference").ToString();

              string filePath = HttpContext.Current.Server.MapPath(line1.CertificateLink);
              if (File.Exists(filePath))
                certificateLinks.Add(line1);
            }
              }
            }
              }

              return certificateLinks;
        }
        private List<int> GetSelectedLineNum()
        {
            List<vw_DeliveryLine> certificates = new List<vw_DeliveryLine>();
              List<int> certificateLinks = new List<int>();

              if (RadGridCertificate.SelectedItems.Count == 0) // no check boxes selected
            return certificateLinks;
              else
              {
            if (radGridCheckBoxSellectAllChecked) // sellect all check box selected
            {
              IQueryable<vw_DeliveryLine> data = GetData();
              certificates = data.Where(c => c.CertificateLink != null).Select(c => c).Distinct().ToList();
            }

            else // some check boxes selected
            {
              GridItemCollection gridItemCollection = RadGridCertificate.SelectedItems;
              foreach (GridDataItem data in gridItemCollection)
              {
            if (data.GetDataKeyValue("CertificateLink") != null)
            {
              vw_DeliveryLine line1 = new vw_DeliveryLine();
              line1.SOLineNum = Convert.ToInt32(data.GetDataKeyValue("SOLineNum"));
              line1.CertificateLink = data.GetDataKeyValue("CertificateLink").ToString();
              certificates.Add(line1);
            }
            // certificateLinks.Add(data.GetDataKeyValue("HeatNumber").ToString());

              }
            }

            //
            //certificateLinks = GetExistingLineNum(certificates);
              }

              return certificateLinks;
        }