I am using Itextsharp for converting Webpage to pdf ,

Following is the code on export button click

protected void btnExport_Click(object sender, EventArgs e)
{
StringWriter sw = new StringWriter();
StringReader sr = new StringReader(sw.ToString());
Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
PdfWriter writer = PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
pdfDoc.Open();
XMLWorkerHelper.GetInstance().ParseXHtml(writer, pdfDoc, sr);
pdfDoc.Close();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=HTML.pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Write(pdfDoc);
Response.End();
}

It gives me error on this line

pdfDoc.Close();

Here is my HTML code ,Can you help to find out error in tags...I am not getting it

<div class="Container" >
   <%--header--%>
 <table style="width: 100%">
   <tr>
   <td style="font-weight: bold;font-size: 14px" colspan="2"><div>
   <span >Bank Name.</span></div></td>
   </tr>
    
  
  <tr>
   <td  colspan="2"><div><span ></span></div></td>
  </tr>
 
 
 <tr >
 <td style="font-size: 10px;height: 50px;width:50%">
   <div>
   <span>Address </span> <br />
   <span></span>
   </div>
 </td>
 <td align="right" style="font-weight: bold;font-size: 10px" > <div> <span>CENTRAL KYC REGISTRY</span><br /><span>KYC Applictaion form | Individual</span></div></td>
 </tr>
   
    
    </table>
  <br />
 
 <%-- personal details--%>
  <table style="width: 100%">
   
    
    
   <tr>
       <td bgcolor="#cccccc" colspan="3" style="height: 29px;font-weight: bold;font-size: 12px">
       <div >1. Personal Details  </div>
       </td>
        
  </tr>
    
   <tr>
       <td style="height: 50px"><div> Name* (Same as ID proof):  <asp:Label ID="lbName" runat="server" Text=""></asp:Label></div></td>
       <td style="width:30%"> </td>
       <td rowspan="4"  style="height:140px"><asp:Image ID="Image1" ImageUrl="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSluPD3muidFFesfs2wk823JQo3HUiL9EpCtXm9sR3wQTyyPW5R" runat="server" /> </td>
   </tr>
 
   <tr>
   <td class="Col1">
   <div> Maiden name (If any)* : <asp:Label ID="lbMaidenName" runat="server" Text=""></asp:Label></div> </td>
   <td style="width:51%">
   </td>
   </tr>
        
   <tr>
   <td class="Col1"><div> Father's/Spouse Name* : <asp:Label ID="lbFatherName" runat="server" Text=""></asp:Label></div></td>
    <td style="width:30%"> </td>
   </tr>
 
   <tr>
   <td class="Col1"><div> Mother name* : <asp:Label ID="Label1" runat="server" Text=""></asp:Label></div></td>
   <td style="width:30%"> </td>
   </tr>
   </table>
 
   <table style="width: 100%">
   <tr>
   <td class="Col3"><div>Date of birth* : <asp:Label ID="Label2" runat="server" Text=""></asp:Label> </div></td>
   <td><div> Gender* : <asp:Label ID="Label3" runat="server" Text=""></asp:Label> </div> </td>
   
   </tr>
 
   <tr>
    <td class="Col3"><div> Marital status* : <asp:Label ID="Label4" runat="server" Text=""></asp:Label></div></td>
   <td><div> Citizenship* : <asp:Label ID="Label5" runat="server" Text=""></asp:Label></div> </td>
   </tr>
 
   <tr>
   <td class="Col3"><div>Residential status* : <asp:Label ID="Label6" runat="server" Text=""></asp:Label> </div></td>
   <td><div> Occupation Type* : <asp:Label ID="Label7" runat="server" Text=""></asp:Label> </div> </td>
   
   </tr>
 
   <tr>
   <td class="Col3">Pan card* :<div><asp:Label ID="Label8" runat="server" Text=""></asp:Label> </div></td>
   <td><div> Adhar Card* :<asp:Label ID="Label9" runat="server" Text=""></asp:Label> </div> </td>
   
   </tr>
   </table>
    
      <br />
       <br />
   </div>