[Zope] How to access a dtml-var from a python method?

Hi everybody, I would like to know how can I access a variable that I have on a html form, for instance, in my python method and work with this variable in python? I tried to pass as a parameter, like def method(<dtml-var variable>): ... if <dtml-var variable> == ... and of course it did not work, I would be really glad if any of you could help me. Thanks in Advance, Rommel Novaes Carvalho