problem with iTextSharp & arabic text

public void PersianSupport(string sFilePDF)
        {
            Document document = new Document();
            try
            {
                PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(sFilePDF, FileMode.Create));
                document.Open();
                string fontpath = Environment.GetEnvironmentVariable("SystemRoot") + "\\fonts\\times.ttf";
                BaseFont basefont = BaseFont.CreateFont(fontpath, BaseFont.IDENTITY_H, true);
                iTextSharp.text.Font arabicFont = new iTextSharp.text.Font(basefont, 24, iTextSharp.text.Font.NORMAL, iTextSharp.text.Color.BLUE);


                var el = new Chunk();
                iTextSharp.text.Font f2 = new iTextSharp.text.Font(basefont, el.Font.Size,
                                                el.Font.Style, el.Font.Color);
                el.Font = f2;
                PdfPTable table = new PdfPTable(1);
                
                table.RunDirection = PdfWriter.RUN_DIRECTION_RTL;
                
                var str = "نام : " ;
                PdfPCell cell = new PdfPCell(new Phrase(10, str, el.Font));
                table.AddCell(cell);

                document.Add(table);
                document.Close();

            }
            catch (DocumentException de)
            {
  //              this.Message = de.Message;
            }
            catch (IOException ioe)
            {
//                this.Message = ioe.Message;
            }

            // step 5: we close the document
            document.Close();


        }