Private Sub convertToPdfButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles convertToPdfButton.Click
    ' 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

    ' Set the PDF file to be inserted before conversion result
    htmlToPdfConverter.PdfDocumentOptions.AddStartDocument(pdfBeforeTextBox.Text)

    ' Set the PDF file to be added after conversion result
    htmlToPdfConverter.PdfDocumentOptions.AddEndDocument(pdfAfterTextBox.Text)

    Cursor = Cursors.WaitCursor

    Dim outPdfFile As String = "DemoAppFiles\Output\HTML_to_PDF\Merge_HTML_with_Existing_PDF.pdf"
    Try
        ' The URL to convert
        Dim url As String = urlTextBox.Text

        ' Convert the HTML page to a PDF document and add the external PDF documents
        Dim outPdfBuffer() As Byte = htmlToPdfConverter.ConvertUrl(url)

        ' Write the memory buffer in a PDF file
        System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer)
    Catch ex As Exception
        ' The HTML to PDF conversion failed
        MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message))
        Return
    Finally
        Cursor = Cursors.Arrow
    End Try

    ' Open the created PDF document in default PDF viewer
    Try
        Process.Start(outPdfFile)
    Catch ex As Exception
        MessageBox.Show(String.Format("Cannot open created PDF file '{0}'. {1}", outPdfFile, ex.Message))
    End Try
End Sub