Pdf creation and send as an mail attachment

I have used the following code in post method
string appl_str = "Dear Sir/Madam,We have received feedback with the following details against your application ID " + "" +dn.Lnd_Program.prgm_id + ":";
appl_str = appl_str + "" + " Applicant Details";
appl_str = appl_str + "";
appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "Name " + fname + " Salary Code " + lnd_app.create_by + " Gender" + dis.gender.ToUpper() + " Father's Name" + award_app.APPL_FATHER + " Mother's Name" + award_app.APPL_MOTHER + " Category" + dis.category.ToUpper() + " Class" + dis.cat_class.ToUpper() + " Institute" + award_app.APPL_SCHOOL_COLLEGE + " Preferred Language" + award_app.APPL_PREFERRED_LANGUAGE + " ";
//appl_str = appl_str + "" + " Applicant Correspondence Address";
//appl_str = appl_str + "";
//appl_str = appl_str + "table, th, td {border: 1px solid black;}th, td {padding: 8px;text-align: center;} Applicant Correspondence Address";
appl_str = appl_str + "";
appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
//appl_str = appl_str + "";
appl_str = appl_str + "Address" + award_app.APPL_ADDR_1 + " " + award_app.APPL_ADDR_2 + " Town/City" + dn.Lnd_Program.agency_name + " District" + dn.Lnd_Program.pgm_city + " State" + dis.add_state + " Pin/City" + award_app.APPL_ADDR_PIN + " Mobile Number/City" + award_app.APPL_MOBILE_NO + " Alternate Mobile Number" + award_app.APPL_ALT_MOBILE_NO + " Email" + award_app.APPL_ADDR_EMAIL + " Submission Date and Time" + dn.Lnd_Program.create_date + " ";
appl_str = appl_str + "For any query please mail us at test@test.in with your application ID.";
appl_str = appl_str + "Regards" + "XYZ" + "";
Response.Clear();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=" + dn.Lnd_Program.prgm_id.ToString() + ".pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.BinaryWrite(GetPDF(appl_str));
Response.End();
But this downloads the pdf file......how to use the above pdf as an mail attachment.

GetPDF Function.....

public byte[] GetPDF(string pHTML)
{
byte[] bPDF = null;

MemoryStream ms = new MemoryStream();
TextReader txtReader = new StringReader(pHTML);

// 1: create object of a itextsharp document class
Document doc = new Document(PageSize.A4, 25, 25, 25, 25);

// 2: we create a itextsharp pdfwriter that listens to the document and directs a XML-stream to a file
PdfWriter oPdfWriter = PdfWriter.GetInstance(doc, ms);

// 3: we create a worker parse the document
HTMLWorker htmlWorker = new HTMLWorker(doc);

// 4: we open document and start the worker on the document
doc.Open();
htmlWorker.StartDocument();


// 5: parse the html into the document
htmlWorker.Parse(txtReader);

// 6: close the document and the worker
htmlWorker.EndDocument();
htmlWorker.Close();
doc.Close();

bPDF = ms.ToArray();

return bPDF;