[Zope] Content-type for a method or script

[Trevor Toenjes]

I need to render an image with some logic from a request in an external
(non-zope page)

example request from html: <img
src="http://zope/images/header.gif?UID=sdflkj">

DTML_Method "header.gif"
<dtml-call "RESPONSE.setHeader('Content-Type', 'image/gif')">
<dtml-var mytestgif>
my ID=<dtml-var UID>

mytestgif is an 'Image' in zope.
It renders fine when I test the URL http://zope/images/header.gif?UID=sdflkj

But, the Method does not render when called from within <img src> in another
page!!!  I got the same result with a script.
Please point me in the right direction...

Thanks
Trevor