[Zope] Content Disposition - Download files

[Bruno Grampa]

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