    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 = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

        // 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 all images from HTML page
        htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementSelectors = new string[] { "img" };

        // Exclude the original images from rendering becuase they will be replaced by an image from local file system
        htmlToPdfConverter.HiddenHtmlElementsSelectors = new string[] { "img" };

        Document pdfDocument = null;
        try
        {
            // Convert a HTML string with images to replace to a PDF document object
            pdfDocument = htmlToPdfConverter.ConvertUrlToPdfDocumentObject(urlTextBox.Text);

            // Replace the images selected in HTML using special attributes with images from local file system
            foreach (HtmlElementMapping imageElementInfo in htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult)
            {
                PdfPage imagePdfPage = imageElementInfo.PdfRectangles[0].PdfPage;
                RectangleF imageRectangle = imageElementInfo.PdfRectangles[0].Rectangle;

                ImageElement newImageElement = new ImageElement(imageRectangle.X, imageRectangle.Y, imageRectangle.Width, imageRectangle.Height,
                                Server.MapPath("~/DemoAppFiles/Input/Images/box.jpg"));
                newImageElement.EnlargeEnabled = true;
                imagePdfPage.AddElement(newImageElement);
            }

            // Save the PDF document in a memory buffer
            byte[] outPdfBuffer = pdfDocument.Save();

            // 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=Replace_with_Higher_Quality_Images.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();
        }
        finally
        {
            // Close the PDF document
            if (pdfDocument != null)
                pdfDocument.Close();
        }
    }