Control 'chksameAddr' of type 'CheckBox' must be placed inside a form tag with runat=server in ASP.Net

Greetings again experts,

I got this awesome code from here - aspsnippets.com:

https://www.aspsnippets.com/Articles/Export-HTML-DIV-contents-to-PDF-using-iTextSharp-in-ASPNet.aspx

    protected void btnExport_Click(object sender, EventArgs e)

    {
        Response.ContentType = "application/pdf";
        Response.AddHeader("content-disposition", "attachment;filename=Panel.pdf");
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        StringWriter sw = new StringWriter();
        HtmlTextWriter hw = new HtmlTextWriter(sw);
        pnlContents.RenderControl(hw);
        StringReader sr = new StringReader(sw.ToString());
        Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 100f, 0f);
        HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
        PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
        pdfDoc.Open();
        htmlparser.Parse(sr);
        pdfDoc.Close();
        Response.Write(pdfDoc);
        Response.End();
    }

In the markup, I am using Multiview control with four views inside it.

Inside one of those views is panel control pnlContents.

I am trying to export contents inside this panel.

Inside this panel control is a checkbox with contol ID called chksameAddr. It has a runat="server" attribute.

All of these are inside a form tag also with a runat="server" attribute.

Code is very long but I mimmicked the code from aspsnippets.com.

The difference is the multiview control.

When I run the code, I get the following error:

Control 'chksameAddr' of type 'CheckBox' must be placed inside a form tag with runat=server.

The error is on this line:

pnlContents.RenderControl(hw);

Any idea how to resolve this?

Many thanks for the continued assistance.