Protected Sub convertToPdfButton_Click(ByVal sender As Object, ByVal e As EventArgs)
    ' Create a HTML to PDF converter object with default settings
    Dim htmlToPdfConverter As 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

    ' Select the HTML elements to bookmark by setting a list of CSS selectors
    htmlToPdfConverter.PdfBookmarkOptions.HtmlElementSelectors = New String() {htmlElementsSelectorTextBox.Text}

    ' Display the bookmarks panel in PDF viewer when the generated PDF is opened
    htmlToPdfConverter.PdfViewerPreferences.PageMode = ViewerPageMode.UseOutlines

    ' Convert the HTML page to a PDF document in a memory buffer
    Dim outPdfBuffer() As Byte = htmlToPdfConverter.ConvertUrl(urlTextBox.Text)

    ' 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_API_Elements_to_Bookmark.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()
End Sub