c# save pdf to folder

protected void save_pdf()
{
   String path_name = "~/PDF/";
   var pdfPath = Path.Combine(Server.MapPath(path_name));
   var formFieldMap = PDFHelper.GetFormFieldNames(pdfPath);

   string username = "Test";
   string password = "12345";      
   String file_name_pdf = "Test.pdf";

   var pdfContents = PDFHelper.GeneratePDF(pdfPath, formFieldMap);

   File.WriteAllBytes(Path.Combine(pdfPath, file_name_pdf), pdfContents);

   WebRequest request = WebRequest.Create(Server.MapPath("~/PDF/" + pdfContents));
   request.Method = WebRequestMethods.Ftp.UploadFile;

   request.Credentials = new NetworkCredential(username, password);
   Stream reqStream = request.GetRequestStream();
   reqStream.Close();
}