private void convertToPdfButton_Click(object sender, EventArgs e)
{
    // Create a HTML to PDF converter object with default settings
    HtmlToPdfConverter htmlToPdfConverter = 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 encryption algorithm and the encryption key size if they are not the default ones
    if (!bit128RadioButton.Checked || !rc4RadioButton.Checked)
    {
        // set the encryption algorithm
        htmlToPdfConverter.PdfSecurityOptions.EncryptionAlgorithm = rc4RadioButton.Checked ? EncryptionAlgorithm.RC4 : EncryptionAlgorithm.AES;
                
        // set the encryption key size
        if (bit40RadioButton.Checked)
            htmlToPdfConverter.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey40Bit;
        else if (bit128RadioButton.Checked)
            htmlToPdfConverter.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey128Bit;
        else if (bit256RadioButton.Checked)
            htmlToPdfConverter.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey256Bit;
    }
            
    // Set user and owner passwords
    if (userPasswordTextBox.Text.Length > 0)
        htmlToPdfConverter.PdfSecurityOptions.UserPassword = userPasswordTextBox.Text;

    if (ownerPasswordTextBox.Text.Length > 0)
        htmlToPdfConverter.PdfSecurityOptions.OwnerPassword = ownerPasswordTextBox.Text;            

    // Set PDF document permissions
    htmlToPdfConverter.PdfSecurityOptions.CanPrint = printEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanPrintHighResolution = highResolutionPrintEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanCopyContent = copyContentEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanCopyAccessibilityContent = copyAccessibilityContentEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanEditContent = editContentEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanEditAnnotations = editAnnotationsEnabledCheckBox.Checked;
    htmlToPdfConverter.PdfSecurityOptions.CanFillFormFields = fillFormFieldsEnabledCheckBox.Checked;

    if ((PermissionsChanged(htmlToPdfConverter) || htmlToPdfConverter.PdfSecurityOptions.UserPassword.Length > 0) &&
        htmlToPdfConverter.PdfSecurityOptions.OwnerPassword.Length == 0)
    {
        // A user password is set but the owner password is not set or the permissions are not the default ones
        // Set a default owner password
        htmlToPdfConverter.PdfSecurityOptions.OwnerPassword = "owner";
    }

    Cursor = Cursors.WaitCursor;

    // Convert HTML to PDF using the settings above
    string outPdfFile = @"DemoAppFiles\Output\HTML_to_PDF\Set_Permissions_Password.pdf";
    try
    {
        // Convert the HTML page to a PDF document in a memory buffer
        byte[] outPdfBuffer = htmlToPdfConverter.ConvertUrl(urlTextBox.Text);

        // Write the memory buffer in a PDF file
        System.IO.File.WriteAllBytes(outPdfFile, outPdfBuffer);
    }
    catch (Exception ex)
    {
        // The HTML to PDF conversion failed
        MessageBox.Show(String.Format("HTML to PDF Error. {0}", ex.Message));
        return;
    }
    finally
    {
        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));
    }
}