protected 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 PDF color space
    // By default the RGB color space is used
    if (grayScaleRadioButton.Checked)
        htmlToPdfConverter.PdfDocumentOptions.ColorSpace = ColorSpace.Gray;
    else if (cmykRadioButton.Checked)
        htmlToPdfConverter.PdfDocumentOptions.ColorSpace = ColorSpace.CMYK;

    // Convert the HTML page to a PDF document in a memory buffer
    byte[] outPdfBuffer = 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=PDF_Color_Space.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();
}