[Zope] advice to track graphics rendering in DTML or python(script)

[Trevor Toenjes]

I have a template that needs to render a different header GIF, based on a
URL variable.
eg: http://zope/images/header.gif?Alkj9876

How do I capture the "UniqueID" in DTML so I can process a DTML-If and
record the ID?

TIA,
Trevor