Private Sub convertToPdfButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles convertToPdfButton.Click
    ' Create a PDF document
    Dim pdfDocument As 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
    Dim pdfPage As PdfPage = pdfDocument.AddPage()

    Cursor = Cursors.WaitCursor

    ' Convert HTML to PDF using the settings above
    Dim outPdfFile As String = "DemoAppFiles\Output\PDF_Creator\Button_JavaScript_Actions.pdf"
    Try
        Dim htmlWithButton As String = htmlStringTextBox.Text
        Dim baseUrl As String = baseUrlTextBox.Text

        ' Add a HTML string with a button to PDF document
        Dim htmlToPdfElement As New HtmlToPdfElement(htmlWithButton, baseUrl)
        pdfPage.AddElement(htmlToPdfElement)

        ' Get the button location in PDF
        Dim buttonMapping As HtmlElementMapping = htmlToPdfElement.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetElementByMappingId("javascript_button")
        If buttonMapping IsNot Nothing Then
            Dim buttonPdfPage As PdfPage = buttonMapping.PdfRectangles(0).PdfPage
            Dim buttonRectangle As RectangleF = buttonMapping.PdfRectangles(0).Rectangle

            ' The font used for buttons text in PDF document
            Dim buttonTextFont As PdfFont = pdfDocument.AddFont(New Font("Times New Roman", 8, FontStyle.Regular, GraphicsUnit.Point))

            ' Create a PDF form button
            Dim pdfButton As PdfFormButton = pdfDocument.Form.AddButton(buttonPdfPage, buttonRectangle, "Execute Acrobat JavaScript", buttonTextFont)

            ' Set JavaScript action to be executed when the button is clicked
            Dim javaScript As String = Nothing
            If alertMessageRadioButton.Checked Then
                ' JavaScript to display an alert mesage 
                javaScript = String.Format("app.alert(""{0}"")", alertMessageTextBox.Text)
            ElseIf printDialogRadioButton.Checked Then
                ' JavaScript to open the print dialog
                javaScript = "print()"
            ElseIf zoomLevelRadioButton.Checked Then
                ' JavaScript to set an initial zoom level 
                javaScript = String.Format("zoom={0}", Integer.Parse(zoomLevelTextBox.Text))
            End If

            ' Set the JavaScript action
            pdfButton.Action = New PdfActionJavaScript(javaScript)
        End If

        ' Save the PDF document in a memory buffer
        Dim outPdfBuffer() As Byte = pdfDocument.Save()

        ' Write the memory buffer in a PDF file
        System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer)
    Catch ex As Exception
        ' 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
    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