Comment positionner et envelopper un long texte?

le PDF que je peux produire en ce moment: capture d'écran http://yart.com.au/junk/itextsharp_problem.jpg

je veux que le texte pour remplir l'espace en bas à gauche. Comment puis-je le faire? Merci!

voici mon code:

private static void CreatePdf4(string pdfFilename, string heading, string text, string[] photos, string emoticon)
{
  Document document = new Document(PageSize.A4.Rotate(), 26, 36, 0, 0);
  PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(pdfFilename, FileMode.Create));
  document.Open();

  // Heading
  Paragraph pHeading = new Paragraph(new Chunk(heading, FontFactory.GetFont(FontFactory.HELVETICA, 54, Font.NORMAL)));
  document.Add(pHeading);

  // Photo 1
  Image img1 = Image.GetInstance(HttpContext.Current.Server.MapPath("/uploads/photos/" + photos[0]));
  img1.ScaleAbsolute(350, 261);
  img1.SetAbsolutePosition(46, 220);
  img1.Alignment = Image.TEXTWRAP;
  document.Add(img1);

  // Photo 2
  Image img2 = Image.GetInstance(HttpContext.Current.Server.MapPath("/uploads/photos/" + photos[1]));
  img2.ScaleAbsolute(350, 261);
  img2.SetAbsolutePosition(438, 220);
  img2.Alignment = Image.TEXTWRAP;
  document.Add(img2);

  // Text

  PdfContentByte cb = writer.DirectContent;
  cb.BeginText();
  cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, false), 18);
  cb.SetTextMatrix(46, 175);
  cb.ShowText(text);
  cb.EndText();

  // Photo 3
  Image img3 = Image.GetInstance(HttpContext.Current.Server.MapPath("/uploads/photos/" + photos[2]));
  img3.ScaleAbsolute(113, 153);
  img3.SetAbsolutePosition(556, 38);
  document.Add(img3);

  // Emoticon
  Image imgEmo = Image.GetInstance(HttpContext.Current.Server.MapPath("/Content/images/" + emoticon));
  imgEmo.ScaleToFit(80, 80);
  imgEmo.SetAbsolutePosition(692, 70);
  document.Add(imgEmo);

  document.Close();
}