protected void btnPDF_Click(object sender, EventArgs e)
        {
            startConversion = true;

        }

       
        protected override void Render(HtmlTextWriter writer)
        {
            if (startConversion)
            {

                // get html of the page
                TextWriter myWriter = new StringWriter();
                HtmlTextWriter htmlWriter = new HtmlTextWriter(myWriter);
                base.Render(htmlWriter);

                // instantiate a html to pdf converter object
                HtmlToPdf converter = new HtmlToPdf();

                // create a new pdf document converting the html string of the page
                PdfDocument doc = converter.ConvertHtmlString(
                    myWriter.ToString(), Request.Url.AbsoluteUri);

                // save pdf document
                doc.Save(Response, false, "D:\\work\\Sample.pdf");

                // close pdf document
                doc.Close();
            }
            else
            {
                // render web page in browser
                base.Render(writer);
            }
        }

        protected void btnPDF_Click(object sender, EventArgs e)
        {
            HtmlToPdf converter = new HtmlToPdf();

            // create a new pdf document converting an url
            PdfDocument doc = converter.ConvertUrl(Request.Url.AbsoluteUri);

            // save pdf document
            doc.Save("D:\\work\\Sample.pdf");

            // close pdf document
            doc.Close();
        }