Export to Pdf using itextsharp

using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp.text.html.simpleparser;
using iTextSharp.text.html;

private void ExporttoPdf()
        {
            SPSecurity.RunWithElevatedPrivileges(delegate()
            {
                try
                {
                    Document document = new Document(PageSize.A4, 25f, 25f, 25f, 25f);
                    string Path = System.IO.Path.GetTempPath() + "Correspondence Report.pdf";
                    if (File.Exists(Path))
                        File.Delete(Path);
                    PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(Path, FileMode.Create));
                    document.Open();
                    PdfPTable pdfgridtable = new PdfPTable(5);
                    pdfgridtable.DefaultCell.FixedHeight = 25;
                    float[] gridwidths = new float[] { 20f, 20f, 20f, 20f, 20f };
                    pdfgridtable.SetWidths(gridwidths);
                    pdfgridtable.WidthPercentage = 100;
                    PdfPCell pdfgridcell1 = new PdfPCell(new Phrase("NAME", new Font(Font.HELVETICA, 7.5f, Font.BOLD, Color.BLACK)));
                    pdfgridcell1.HorizontalAlignment = Element.ALIGN_CENTER;
                    pdfgridcell1.PaddingTop = 1f;
                    pdfgridcell1.PaddingBottom = 4f;
                    pdfgridtable.AddCell(pdfgridcell1);
                    PdfPCell pdfgridcell2 = new PdfPCell(new Phrase("SUBJECT", new Font(Font.HELVETICA, 7.5f, Font.BOLD, Color.BLACK)));
                    pdfgridcell2.HorizontalAlignment = Element.ALIGN_CENTER;
                    pdfgridcell2.PaddingTop = 1f;
                    pdfgridcell2.PaddingBottom = 4f;
                    pdfgridtable.AddCell(pdfgridcell2);
                    PdfPCell pdfgridcell3 = new PdfPCell(new Phrase("SENDER NAME", new Font(Font.HELVETICA, 7.5f, Font.BOLD, Color.BLACK)));
                    pdfgridcell3.HorizontalAlignment = Element.ALIGN_CENTER;
                    pdfgridcell3.PaddingTop = 1f;
                    pdfgridcell3.PaddingBottom = 4f;
                    pdfgridtable.AddCell(pdfgridcell3);
                    PdfPCell pdfgridcell4 = new PdfPCell(new Phrase("RECEIVED DATE", new Font(Font.HELVETICA, 7.5f, Font.BOLD, Color.BLACK)));
                    pdfgridcell4.HorizontalAlignment = Element.ALIGN_CENTER;
                    pdfgridcell4.PaddingTop = 1f;
                    pdfgridcell4.PaddingBottom = 4f;
                    pdfgridtable.AddCell(pdfgridcell4);
                    PdfPCell pdfgridcell5 = new PdfPCell(new Phrase("SUBJECT CATEGORY", new Font(Font.HELVETICA, 7.5f, Font.BOLD, Color.BLACK)));
                    pdfgridcell5.HorizontalAlignment = Element.ALIGN_CENTER;
                    pdfgridcell5.PaddingTop = 1f;
                    pdfgridcell5.PaddingBottom = 4f;
                    pdfgridcell5.NoWrap = false;
                    pdfgridtable.AddCell(pdfgridcell5);
                    PdfPCell pdfgridcell11 = null;
                    PdfPCell pdfgridcell22 = null;
                    PdfPCell pdfgridcell33 = null;
                    PdfPCell pdfgridcell44 = null;
                    PdfPCell pdfgridcell55 = null;
                    foreach (GridViewRow gvrow in gvReportview.Rows)
                    {
                        for (int i = 0; i < gvrow.Cells.Count; i++)
                        {
                            string CellText = string.Empty;
                            if (i == 0)
                            {
                                Label lblreferenceno = (Label)gvrow.FindControl("lblreferenceno");
                                if (!string.IsNullOrEmpty(lblreferenceno.Text))
                                    CellText = lblreferenceno.Text;
                                else
                                {
                                    HyperLink lnkview = (HyperLink)gvrow.FindControl("lnkview");
                                    CellText = lnkview.Text;
                                }
                                if (String.IsNullOrEmpty(CellText))
                                    CellText = " ";
                                pdfgridcell11 = new PdfPCell(new Phrase(CellText.Replace("&nbsp;", " "), new Font(Font.HELVETICA, 7.5f, Font.NORMAL, Color.BLACK)));
                                pdfgridcell11.HorizontalAlignment = Element.ALIGN_LEFT;
                                pdfgridcell11.PaddingBottom = 6f;
                                pdfgridcell11.PaddingTop = 1f;
                                pdfgridcell11.Padding = 5f;
                                pdfgridtable.AddCell(pdfgridcell11);
                            }
                            else if (i == 1)
                            {
                                Label lblreferenceno = (Label)gvrow.FindControl("lbltitle");
                                if (!string.IsNullOrEmpty(lblreferenceno.Text))
                                    CellText = lblreferenceno.Text;
                                if (String.IsNullOrEmpty(CellText))
                                    CellText = " ";
                                pdfgridcell22 = new PdfPCell(new Phrase(CellText.Replace("&nbsp;", " "), new Font(Font.HELVETICA, 7.5f, Font.NORMAL, Color.BLACK)));
                                pdfgridcell22.HorizontalAlignment = Element.ALIGN_LEFT;
                                pdfgridcell22.PaddingBottom = 6f;
                                pdfgridcell22.PaddingTop = 1f;
                                pdfgridcell22.Padding = 5f;
                                pdfgridtable.AddCell(pdfgridcell22);
                            }
                            else if (i == 2)
                            {
                                Label lblreferenceno = (Label)gvrow.FindControl("lblsender");
                                if (!string.IsNullOrEmpty(lblreferenceno.Text))
                                    CellText = lblreferenceno.Text;
                                if (String.IsNullOrEmpty(CellText))
                                    CellText = " ";
                                pdfgridcell33 = new PdfPCell(new Phrase(CellText.Replace("&nbsp;", " "), new Font(Font.HELVETICA, 7.5f, Font.NORMAL, Color.BLACK)));
                                pdfgridcell33.HorizontalAlignment = Element.ALIGN_LEFT;
                                pdfgridcell33.PaddingBottom = 6f;
                                pdfgridcell33.PaddingTop = 1f;
                                pdfgridcell33.Padding = 5f;
                                pdfgridtable.AddCell(pdfgridcell33);
                            }
                            else if (i == 3)
                            {
                                Label lblreferenceno = (Label)gvrow.FindControl("lblreceiveddate");
                                if (!string.IsNullOrEmpty(lblreferenceno.Text))
                                    CellText = lblreferenceno.Text;
                                if (String.IsNullOrEmpty(CellText))
                                    CellText = " ";
                                pdfgridcell44 = new PdfPCell(new Phrase(CellText.Replace("&nbsp;", " "), new Font(Font.HELVETICA, 7.5f, Font.NORMAL, Color.BLACK)));
                                pdfgridcell44.HorizontalAlignment = Element.ALIGN_LEFT;
                                pdfgridcell44.PaddingBottom = 6f;
                                pdfgridcell44.PaddingTop = 1f;
                                pdfgridcell44.Padding = 5f;
                                pdfgridtable.AddCell(pdfgridcell44);
                            }
                            else if (i == 4)
                            {
                                Label lblreferenceno = (Label)gvrow.FindControl("lblsubject");
                                if (!string.IsNullOrEmpty(lblreferenceno.Text))
                                    CellText = lblreferenceno.Text;

                                if (String.IsNullOrEmpty(CellText))
                                    CellText = " ";
                                pdfgridcell55 = new PdfPCell(new Phrase(CellText.Replace("&nbsp;", " "), new Font(Font.HELVETICA, 7.5f, Font.NORMAL, Color.BLACK)));
                                pdfgridcell55.HorizontalAlignment = Element.ALIGN_LEFT;
                                pdfgridcell55.PaddingBottom = 6f;
                                pdfgridcell55.PaddingTop = 1f;
                                pdfgridcell55.Padding = 5f;
                                pdfgridtable.AddCell(pdfgridcell55);
                            }
                        }
                    }

                    document.Add(pdfgridtable);
                    document.Close();
                    ShowPdf(Path);
                }
                catch (Exception ex)
                {
                    lblMsg.ForeColor = System.Drawing.Color.Red;
                    lblMsg.Text = ex.Message.ToString();
                }
            });
        }

private void ShowPdf(string strS)
        {
            try
            {
                Response.ClearContent();
                Response.ClearHeaders();
                if (strS.Contains("xls"))
                    Response.ContentType = "application/xls";
                else if (strS.Contains("xls"))
                    Response.ContentType = "application/pdf";
                Response.AddHeader
                ("Content-Disposition", "attachment; filename=" + strS);
                //Response.TransmitFile(strS);
                //Response.End();
                Response.WriteFile(strS);
                Response.Flush();
                Response.Clear();
            }
            catch (Exception ex)
            {
                lblMsg.ForeColor = System.Drawing.Color.Red;
                lblMsg.Text = ex.Message.ToString();
            }
        }