private void convertToPdfButton_Click(object sender, EventArgs e)
{
    // Create a PDF document
    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 = "fvDh8eDx4fHg4P/h8eLg/+Dj/+jo6Og=";

    // Add a page to PDF document
    PdfPage pdfPage = pdfDocument.AddPage();

    Cursor = Cursors.WaitCursor;

    string outPdfFile = @"DemoAppFiles\Output\PDF_Creator\Set_Initial_Zoom_Level.pdf";
    try
    {
        // Create a HTML to PDF element to add to document
        HtmlToPdfElement htmlToPdfElement = new HtmlToPdfElement(urlTextBox.Text);

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

        // Add the HTML to PDF element to document
        pdfPage.AddElement(htmlToPdfElement);

        int goToPageNumber = int.Parse(pageNumberTextBox.Text);
        if (goToPageNumber > pdfDocument.Pages.Count)
        {
            MessageBox.Show("The page number is too big");
            return;
        }

        // Get destination PDF page
        PdfPage goToPage = pdfDocument.Pages[goToPageNumber - 1];

        // Get the destination point in PDF page
        float goToX = float.Parse(xLocationTextBox.Text);
        float goToY = float.Parse(yLocationTextBox.Text);

        PointF goToLocation = new PointF(goToX, goToY);

        // Get the destination view mode
        DestinationViewMode viewMode = SelectedViewMode();

        // Create the destination in PDF document
        ExplicitDestination goToDestination = new ExplicitDestination(goToPage, goToLocation, viewMode);

        // Set the zoom level when the destination is displayed
        if (viewMode == DestinationViewMode.XYZ)
            goToDestination.ZoomPercentage = int.Parse(zoomLevelTextBox.Text);

        // Set the document Go To open action
        pdfDocument.OpenAction.Action = new PdfActionGoTo(goToDestination);

        // 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 PDF creation failed
        MessageBox.Show(String.Format("Create PDF Document 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));
    }
}