PDFwriter -PushButton-perform action "Back to previous page"

Question

Hi,
  I have registration page. I generate PDF using button click. It generates PDF. Now, the problem is, after generate in to PDF, if I want to go to Previous page then I use browser back button. I want to use seperate button in PDF which performs "back to previous page option". I'm not identify how to do this? I search about PushButton inPDF files. But using this how i perform the action . Can anyone help me to do this? I include my  code here.

 protected void btnUpload_Click(object sender, EventArgs e)

        {

            Document pdfDoc = new Document(PageSize.A4, 10, 10, 10, 10);

            try

            {

                PdfWriter.GetInstance(pdfDoc, System.Web.HttpContext.Current.Response.OutputStream);

                pdfDoc.Open();

                //Set Font Properties for PDF File

                Font fnt = FontFactory.GetFont("Times New Roman", 14);

                PdfPTable PdfTable = new PdfPTable(1);

                //PdfPCell PdfPCell = null;

                //Retrieve content from design side

                string pntype = "Patient Type  : ";

                string ptype = ddlpatienttype.SelectedItem.Text;

                PdfPCell ptypeval = new PdfPCell(new Phrase(new Chunk(pntype + ptype)));

                PdfTable.AddCell(ptypeval);

                string pnamel = "Name : ";

                string pnamet = "";

                if (rdbtnmr.Checked == true)

                {

                    pnamet = lblsalutmr.Text + " " + txtPFirstName.Text + " " + txtPMiddleName.Text + " " + txtPLastName.Text;

                }

                else if (rdbtnms.Checked == true)

                {

                    pnamet = lblsalutms.Text + " " + txtPFirstName.Text + " " + txtPMiddleName.Text + " " + txtPLastName.Text;

                }

                else

                //if (rdbtnmrs.Checked == true)

                {

                    pnamet = lblsalutmrs.Text + " " + txtPFirstName.Text + " " + txtPMiddleName.Text + " " + txtPLastName.Text;

                }

               

                PdfPCell pnameval = new PdfPCell(new Phrase(new Chunk(pnamel + pnamet)));

                PdfTable.AddCell(pnameval);

                string pdobl = "DOB : ";

                string pdobt = ddlMonth.SelectedItem.Text + "/" + txtDateOfBirth.Text + "/" + txtBDayYear.Text;

                PdfPCell pdobval = new PdfPCell(new Phrase(new Chunk(pdobl + pdobt)));

                PdfTable.AddCell(pdobval);

                string pgenderl = "Gender : ";

                string pgenderrad = "";

                if (rdbtnmale.Checked == true)

                {

                    pgenderrad = lblmale.Text;

                }

                else if (rdbtnfemale.Checked == true)

                {

                    pgenderrad = lblfemale.Text;

                }

                //string pgenderrad = ddlGender.SelectedItem.Text;

                PdfPCell pgenderval = new PdfPCell(new Phrase(new Chunk(pgenderl + pgenderrad)));

                PdfTable.AddCell(pgenderval);

                string pdoct = "Doctor : ";

                string pdoctdrop = ddlConsultingDoc.SelectedItem.Text;

                PdfPCell pdoctval = new PdfPCell(new Phrase(new Chunk(pdoct + pdoctdrop)));

                PdfTable.AddCell(pdoctval);

                string pAddresstype = "Address Type : ";

                string pAddressDrop = ddladdresstype.SelectedItem.Text;

                PdfPCell pAddressval = new PdfPCell(new Phrase(new Chunk(pAddresstype + pAddressDrop)));

                PdfTable.AddCell(pAddressval);

                string pAddressline1 = "Address Line1 : ";

                string pAddresstext = txtaddressline1.Text;

                PdfPCell pAddressline1val = new PdfPCell(new Phrase(new Chunk(pAddressline1 + pAddresstext)));

                PdfTable.AddCell(pAddressline1val);

                string pAddressline2 = "Address Line2 : ";

                string pAddresstext2 = txtaddressline2.Text;

                PdfPCell pAddressline2val = new PdfPCell(new Phrase(new Chunk(pAddressline2 + pAddresstext2)));

                PdfTable.AddCell(pAddressline2val);

                string pAddressline3 = "Address Line3 : ";

                string pAddresstext3 = txtaddressline3.Text;

                PdfPCell pAddressline3val = new PdfPCell(new Phrase(new Chunk(pAddressline3 + pAddresstext3)));

                PdfTable.AddCell(pAddressline3val);

                string pcity = "City : ";

                string pcitytext = txtcity.Text;

                PdfPCell pcitytextval = new PdfPCell(new Phrase(new Chunk(pcity + pcitytext)));

                PdfTable.AddCell(pcitytextval);

                string ppostalcode = "Postal Code : ";

                string pposttext = txtpostalcode.Text;

                PdfPCell pposttextval = new PdfPCell(new Phrase(new Chunk(ppostalcode + pposttext)));

                PdfTable.AddCell(pposttextval);

                string pcountry = "Country : ";

                string pcountrytext = txtcountry.Text;

                PdfPCell pcountrytextval = new PdfPCell(new Phrase(new Chunk(pcountry + pcountrytext)));

                PdfTable.AddCell(pcountrytextval);

               

                

               

                

                string pgname = "Guardian Name : ";

                string pgnametext = "";

                if (rbsalmr.Checked == true)

                {

                    pgnametext = lblsalmr.Text + " " + txtGFirstName.Text + " " + txtgmiddlename.Text + " " + txtGLastName.Text;

                }

                else if (rbsalms.Checked == true)

                {

                    pgnametext = lblsalms.Text + " " + txtGFirstName.Text + " " + txtgmiddlename.Text + " " + txtGLastName.Text;

                }

                else

                {

                    pgnametext = lblsalmrs.Text + " " + txtGFirstName.Text + " " + txtgmiddlename.Text + " " + txtGLastName.Text;

                }

              

                PdfPCell pgnametextval = new PdfPCell(new Phrase(new Chunk(pgname + pgnametext)));

                PdfTable.AddCell(pgnametextval);

                string pRelationshipname = "RelationShip : ";

                string pRelationshiptext = ddlRelationShip.SelectedItem.Text;

                PdfPCell pRelationshiptextval = new PdfPCell(new Phrase(new Chunk(pRelationshipname + pRelationshiptext)));

                PdfTable.AddCell(pRelationshiptextval);

                string pgdobl = "DOB : ";

                string pgdobt = ddlGMonth.SelectedItem.Text + "/" + txtGDate.Text + "/" + txtGYear.Text;

                PdfPCell pgdobval = new PdfPCell(new Phrase(new Chunk(pgdobl + pgdobt)));

                PdfTable.AddCell(pgdobval);

                string pggenderl = "Gender : ";

                string pggenderrad = "";

                if (rbmale.Checked == true)

                {

                    pggenderrad = lblgmale.Text;

                }

                else

                {

                    pggenderrad = lblgfemale.Text;

                }

            

                PdfPCell pggenderval = new PdfPCell(new Phrase(new Chunk(pggenderl + pggenderrad)));

                PdfTable.AddCell(pggenderval);

                pdfDoc.Add(PdfTable);

                pdfDoc.Close();

                Response.ContentType = "application/pdf";

                System.Web.HttpContext.Current.Response.Write(pdfDoc);

                Response.Flush();

                Response.End();

            }

            catch (Exception ex)

            {

                Response.Write(ex.ToString());

            }

        }