    private void convertToPdfButton_Click(object sender, EventArgs e)
    {
        // Create the PDF document where to add the HTML documents
        Document pdfDocument = new Document();

        // Set license key received after purchase to use the converter in licensed mode
        // Leave it not set to use the converter in demo mode
        pdfDocument.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

        // Create a PDF page where to add the first HTML
        PdfPage firstPdfPage = pdfDocument.AddPage();

        Cursor = Cursors.WaitCursor;
        string outPdfFile = @"DemoAppFiles\Output\HTML_to_PDF\Merge_Multipe_HTML.pdf";
        try
        {
            // Create the first HTML to PDF element
            HtmlToPdfElement firstHtml = new HtmlToPdfElement(0, 0, firstUrlTextBox.Text);

            // Optionally set a delay before conversion to allow asynchonous scripts to finish
            firstHtml.ConversionDelay = 2;

            // Add the first HTML to PDF document
            AddElementResult firstAddResult = firstPdfPage.AddElement(firstHtml);

            PdfPage secondPdfPage = null;
            PointF secondHtmlLocation = Point.Empty;

            if (startNewPageCheckBox.Checked)
            {
                // Create a PDF page where to add the second HTML
                secondPdfPage = pdfDocument.AddPage();
                secondHtmlLocation = PointF.Empty;
            }
            else
            {
                // Add the second HTML on the PDF page where the first HTML ended
                secondPdfPage = firstAddResult.EndPdfPage;
                secondHtmlLocation = new PointF(firstAddResult.EndPageBounds.Left, firstAddResult.EndPageBounds.Bottom);
            }

            // Create the second HTML to PDF element
            HtmlToPdfElement secondHtml = new HtmlToPdfElement(secondHtmlLocation.X, secondHtmlLocation.Y, secondUrlTextBox.Text);

            // Optionally set a delay before conversion to allow asynchonous scripts to finish
            secondHtml.ConversionDelay = 2;

            // Add the second HTML to PDF document
            secondPdfPage.AddElement(secondHtml);

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

            // Write the memory buffer in a PDF file
            System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer);
        }
        catch (Exception ex)
        {
            // The HTML to PDF conversion failed
            MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message));
            return;
        }
        finally
        {
            // Close the PDF document
            pdfDocument.Close();

            Cursor = Cursors.Arrow;
        }

        // Open the created PDF document in default PDF viewer
        try
        {
            System.Diagnostics.Process.Start(outPdfFile);
        }
        catch (Exception ex)
        {
            MessageBox.Show(String.Format("Cannot open created PDF file '{0}'. {1}", outPdfFile, ex.Message));
        }
    }