[Zope] Content Disposition - Download files

Hello, i want to send an image or a pdf to a browser not for viewing but for downloading. I've written this code: <dtml-call "RESPONSE.setHeader('Content-type', 'application/force-download')"> <dtml-call "RESPONSE.setHeader('Content-Disposition', 'attachment; filename=filename.gif')"> now i have to send the file as a binary flow, but i don't know how to do. Can you help me? Thanks, Bruno