calling ZPT from script python - problem

hi
i am having a very weird experience. I have a page template called 
manageheads. This requires a parameter called 'companyname' to be 
passed to it. I access this option as:
python:somefunction(companyname=options['companyname'])
when i call the ZPT from the web like so:
http://.../manageheads?companyname=nameofcompany
it works
but if i call it from a python script like so:
return manageheads(companyname=nameofcompany)
it complains saying
key error 'companyname'

The weird thing is that i have several similar ZPTs where this call 
from python scripts work perfectly in the same zope instance. So why 
not in this one? any clues?
-- 
regards
kg

http://www.livejournal.com/users/lawgon
tally ho! http://avsap.org.in
ಇಂಡ್ಲಿನಕ್ಸ வாழ்க!