protected void convertToPdfButton_Click(object sender, EventArgs e)
{
    // Create a HTML to PDF converter object with default settings
    HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter();

    // Set license key received after purchase to use the converter in licensed mode
    // Leave it not set to use the converter in demo mode
    htmlToPdfConverter.LicenseKey = "fvDh8eDx4fHg4P/h8eLg/+Dj/+jo6Og=";

    // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
    // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
    htmlToPdfConverter.ConversionDelay = 2;

    Document pdfDocument = null;
    try
    {
        // Convert HTML page or string with mapping attributes to a PDF document object 
        // The document can be further modified to highlight the selected elements
        if (convertHtmlRadioButton.Checked)
        {
            string htmlWithMappingAttributes = htmlStringTextBox.Text;
            string baseUrl = baseUrlTextBox.Text;

            // Convert a HTML string with mapping attributes to a PDF document object
            pdfDocument = htmlToPdfConverter.ConvertHtmlToPdfDocumentObject(htmlWithMappingAttributes, baseUrl);
        }
        else
        {
            string url = urlTextBox.Text;

            // Convert a HTML page with mapping attributes to a PDF document object
            pdfDocument = htmlToPdfConverter.ConvertUrlToPdfDocumentObject(url);
        }

        // Display detailed information about the selected elements
        StringBuilder htmlElementInfoBuilder = new StringBuilder();
        foreach (HtmlElementMapping htmlElementInfo in htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult)
        {
            // Get other information about HTML element
            string htmlElementTagName = htmlElementInfo.HtmlElementTagName;
            string htmlElementID = htmlElementInfo.HtmlElementId;
            string htmlElementMappingID = htmlElementInfo.MappingId;
            string htmlElementCssClasssName = htmlElementInfo.HtmlElementCssClassName;
            string htmlElementHtmlCode = htmlElementInfo.HtmlElementOuterHtml;
            string htmlElementInnerHtml = htmlElementInfo.HtmlElementInnerHtml;
            string htmlElementText = htmlElementInfo.HtmlElementText;
            System.Collections.Specialized.NameValueCollection htmlElementAttributes = htmlElementInfo.HtmlElementAttributes;
            HtmlElementPdfRectangle[] htmlElementRectanglesInPdf = htmlElementInfo.PdfRectangles;

            htmlElementInfoBuilder.AppendFormat("<br/>---------------------------------------- HTML Element Info ----------------------------------------<br/><br/>");
            htmlElementInfoBuilder.AppendFormat("<b>Tag Name:</b> {0}<br/>", htmlElementTagName);
            htmlElementInfoBuilder.AppendFormat("<b>Element ID:</b> {0}<br/>", htmlElementID);
            htmlElementInfoBuilder.AppendFormat("<b>Mapping ID:</b> {0}<br/>", htmlElementMappingID);
            htmlElementInfoBuilder.AppendFormat("<b>Text:</b> {0}<br/>", htmlElementText);

            htmlElementInfoBuilder.AppendFormat("<b>Attributes:</b><br/>");
            for (int i = 0; i < htmlElementAttributes.Count; i++)
                htmlElementInfoBuilder.AppendFormat("&nbsp;&nbsp;&nbsp;{0} = \"{1}\"<br/>", htmlElementAttributes.GetKey(i), htmlElementAttributes.Get(i));


            htmlElementInfoBuilder.AppendFormat("<b>Location in PDF:</b><br/>");
            for (int i = 0; i < htmlElementRectanglesInPdf.Length; i++)
            {
                PdfPage pdfPage = htmlElementRectanglesInPdf[i].PdfPage;
                int pdfPageIndex = htmlElementRectanglesInPdf[i].PageIndex;
                RectangleF rectangleInPdfPage = htmlElementRectanglesInPdf[i].Rectangle;

                htmlElementInfoBuilder.AppendFormat("&nbsp;&nbsp;&nbsp;PDF Page Index: {0}<br>", pdfPageIndex);
                htmlElementInfoBuilder.AppendFormat("&nbsp;&nbsp;&nbsp;Rectangle: X = {0:N2} pt , Y = {1:N2} pt , W = {2:N2} pt , H = {3:N2} pt<br/>",
                        rectangleInPdfPage.X, rectangleInPdfPage.Y, rectangleInPdfPage.Width, rectangleInPdfPage.Height);
            }

            htmlElementInfoBuilder.AppendFormat("<br/>");
        }

        PdfPage lastPdfPage = htmlToPdfConverter.ConversionSummary.LastPdfPage;
        RectangleF lastPageRectangle = htmlToPdfConverter.ConversionSummary.LastPageRectangle;

        HtmlToPdfElement htmlElementInfoHtml = new HtmlToPdfElement(0, lastPageRectangle.Bottom + 1, htmlElementInfoBuilder.ToString(), null);
        lastPdfPage.AddElement(htmlElementInfoHtml);

        // Save the PDF document in a memory buffer
        byte[] outPdfBuffer = pdfDocument.Save();

        // Send the PDF as response to browser

        // Set response content type
        Response.AddHeader("Content-Type", "application/pdf");

        // Instruct the browser to open the PDF file as an attachment or inline
        Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Select_in_HTML_Elements_to_Retrieve.pdf; size={0}", outPdfBuffer.Length.ToString()));

        // Write the PDF document buffer to HTTP response
        Response.BinaryWrite(outPdfBuffer);

        // End the HTTP response and stop the current page processing
        Response.End();
    }
    finally
    {
        // Close the PDF document
        if (pdfDocument != null)
            pdfDocument.Close();
    }
}