[Zope] Optional parameters

[Lee Shakespeare]

Hi Folks.

This might be the first of a few quick newbie questions.  I hope that
this is the best place to ask, please let me know if there's somewhere
better.

Is it possible to have optional parameters to a Zope python script?  If
I include the variable in the list of parameters and don't pass it in
the form, Zope complains.  If I don't include it in the parameters and
try to access it Zope complains.  

Zope has been complaining at me a lot this morning :)

TIA.  
Lee.

-- 
Lee Shakespeare   :   lee at webfoundry dot co dot uk