Create PDF using IText Sharp Asp.net

iTextSharp.text.Document doc = new iTextSharp.text.Document(iTextSharp.text.PageSize.A4, 10, 10, 42, 35);
PdfWriter wri = PdfWriter.GetInstance(doc, new FileStream(targetFilename, FileMode.Create));
//Open Document to write
doc.Open();
//Create PdfPtable and add to document
doc.Add(table);
doc.Close();
doc.CloseDocument();