I am not able to create a PDf with Image using iTextSharp and send email

Unable to cast object of type 'iTextSharp.text.html.simpleparser.IncCell' to type 'iTextSharp.text.Rectangle'.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidCastException: Unable to cast object of type 'iTextSharp.text.html.simpleparser.IncCell' to type 'iTextSharp.text.Rectangle'.


I have attached the code for reference

<pre lang="C#">string companyName = "abc";
int orderNo = 2303;
#region String Builder
//
String lUrl = @"http://siansoft.com/zamzam/signimage/zamzamoil.jpg";
StringBuilder sb = new StringBuilder();
sb.Append("<table width='100%' cellspacing='0' cellpadding='2'>");
sb.Append("<tr><td align='left' style='background-color: #18B5F0' colspan = '2'><b>Hi, Javed,</b></td></tr>");
sb.Append("<tr><td align='left' style='background-color: #18B5F0' colspan = '2'><b> Thank you for ordering for TZS 1000.00, The Order delivered. The Order detail is as follows,</b></td></tr>");
sb.Append("</table>");
sb.Append("<br />");
sb.Append("<table border = '1'>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Order No.</b></td>");
sb.Append("<td align='left' colspan = '2'><b>40</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Delivery No.</b></td>");
sb.Append("<td align='left' colspan = '2'><b>98</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Delivery Date</b></td>");
sb.Append("<td align='left' colspan = '2'><b>27/10/2015</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Product</b></td>");
sb.Append("<td align='left' colspan = '2'><b>Petrol</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Qty</b></td>");
sb.Append("<td align='left' colspan = '2'><b>10.00</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Rate</b></td>");
sb.Append("<td align='left' colspan = '2'><b>100.00</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Amount</b></td>");
sb.Append("<td align='left' colspan = '2'><b>1000.00</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Pump No.</b></td>");
sb.Append("<td align='left' colspan = '2'><b>1</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Location</b></td>");
sb.Append("<td align='left' colspan = '2'><b>Engen Ubungo</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Vehicle</b></td>");
sb.Append("<td align='left' colspan = '2'><b>T 929 CDG</b></td>");
sb.Append("</tr>");
sb.Append("<tr>");
sb.Append("<td align='left' colspan = '2'><b>Driver</b></td>");
sb.Append("<td align='left' colspan = '2'><b>Prakash</b></td>");
sb.Append("</tr>");
sb.Append("</table>");
sb.Append("<table>");
sb.Append("<tr>");
sb.Append("<td>Driver's Signature</td>");
sb.Append("</tr>");

sb.Append("<tr>");
sb.Append("<td>http://siansoft.com/zamzam/signimage/sign_98.jpg</td>");
sb.Append("<td style='padding-top:3px;border:solid 1px orange;text-align:center'><a href='htt p://siansoft.com/zamzam/signimage'><img src=" + lUrl + " style='height:55px;width:220px;border-style:solid; padding-left:50px/></a></td>");
sb.Append("</tr>");
sb.Append("</table>");





//sb.Append("<img src='http://siansoft.com/zamzam/signimage/sign_98.jpg' alt='Driver Signature' style='width:304px;height:228px;'>");
#endregion String Builder
StringReader sr = new StringReader(sb.ToString());

Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
using (MemoryStream memoryStream = new MemoryStream())
{
    PdfWriter writer = PdfWriter.GetInstance(pdfDoc, memoryStream);
    pdfDoc.Open();
    htmlparser.Parse(sr);
    pdfDoc.Close();
    byte[] bytes = memoryStream.ToArray();
    memoryStream.Close();

    MailMessage mm = new MailMessage("appfoms@gmail.com", "zamzam_ubungo@zamzamenergy.com");

    mm.Subject = "Order NO.: 50 - Delivered...";
    mm.Body = "Hi Javed, " + System.Convert.ToChar(13).ToString() + "Order No.:50  Delivered, The delvery detail attached for your reference.";
    mm.Attachments.Add(new Attachment(new MemoryStream(bytes), "OrderNo50.pdf"));
    mm.IsBodyHtml = true;
    SmtpClient smtp = new SmtpClient();
    smtp.Host = "smtp.gmail.com";
    smtp.EnableSsl = true;
    NetworkCredential NetworkCred = new NetworkCredential();
    NetworkCred.UserName = "appfoms@gmail.com";
    NetworkCred.Password = "123foms123";
    smtp.UseDefaultCredentials = true;
    smtp.Credentials = NetworkCred;
    smtp.Port = 587;
    smtp.Send(mm);