private void createPdfButton_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();

    // Add second page to PDF document
    PdfPage secondPdfPage = pdfDocument.AddPage();

    // Add third page to PDF document
    PdfPage thirdPdfPage = pdfDocument.AddPage();

    Cursor = Cursors.WaitCursor;
    string outPdfFile = @"DemoAppFiles\Output\PDF_Creator\Internal_Links.pdf";
    try
    {
        // The titles font used to mark various sections of the PDF document
        PdfFont titleFont = pdfDocument.AddFont(new Font("Times New Roman", 10, FontStyle.Bold, GraphicsUnit.Point));
        PdfFont subtitleFont = pdfDocument.AddFont(new Font("Times New Roman", 8, FontStyle.Regular, GraphicsUnit.Point));

        // The links text font
        PdfFont linkTextFont = pdfDocument.AddFont(new Font("Times New Roman", 8, FontStyle.Bold, GraphicsUnit.Point));
        linkTextFont.IsUnderline = true;

        float xLocation = 5;
        float yLocation = 5;

        // Add document title
        TextElement titleTextElement = new TextElement(xLocation, yLocation, "Create Internal Links in PDF Document", titleFont);
        AddElementResult addElementResult = pdfPage.AddElement(titleTextElement);

        yLocation = addElementResult.EndPageBounds.Bottom + 15;

        // Add a text in second page
        TextElement secondPageTextElement = new TextElement(5, 5, "This text is the target of an internal text link", subtitleFont);
        secondPdfPage.AddElement(secondPageTextElement);

        // Add a text in third page
        TextElement thirdPageTextElement = new TextElement(5, 5, "This text is the target of an internal image link", subtitleFont);
        thirdPdfPage.AddElement(thirdPageTextElement);

        // Make a text in PDF an internal link to the second page of the PDF document

        // Add the text element
        string text = "Click this text to go to the second page of this document!";
        float textWidth = linkTextFont.GetTextWidth(text);
        TextElement linkTextElement = new TextElement(xLocation, yLocation, text, linkTextFont);
        linkTextElement.ForeColor = Color.Navy;
        addElementResult = pdfPage.AddElement(linkTextElement);

        // Make the text element an internal link to the second page of this document
        RectangleF linkRectangle = new RectangleF(xLocation, yLocation, textWidth, addElementResult.EndPageBounds.Height);
        // Create the destination in second page
        ExplicitDestination secondPageDestination = new ExplicitDestination(secondPdfPage, new PointF(5,5));
        // Create the internal link from text element to second page
        InternalLinkElement internalLink = new InternalLinkElement(linkRectangle, secondPageDestination);

        // Add the internal link to PDF document
        pdfPage.AddElement(internalLink);

        yLocation = addElementResult.EndPageBounds.Bottom + 10;

        // Make an image in PDF an internal link to the third page of the PDF document

        TextElement subtitleTextElement = new TextElement(xLocation, yLocation, "Click the image below to go to the third page of this document:", subtitleFont);
        addElementResult = pdfPage.AddElement(subtitleTextElement);

        yLocation = addElementResult.EndPageBounds.Bottom + 5;

        // Add the image element
        ImageElement linkImageElement = new ImageElement(xLocation, yLocation, 120, @"DemoAppFiles\Input\Images\logo.jpg");
        addElementResult = pdfPage.AddElement(linkImageElement);

        // Make the image element an internal link to the third page of this document
        linkRectangle = addElementResult.EndPageBounds;
        // Create the destination in third page
        ExplicitDestination thirdPageDestination = new ExplicitDestination(thirdPdfPage, new PointF(5, 5));
        // Create the internal link from image element to third page
        internalLink = new InternalLinkElement(linkRectangle, thirdPageDestination);

        // Add the internal link to PDF document
        pdfPage.AddElement(internalLink);

        // 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));
    }
}