[Zope] General variable use

Hi! I have a general question about calling variables - or maybe calling functions... the best way is to show with an example. I think you can tell what I'm trying to do here: <dtml-var expr="get_your_info(name=<dtml-var expr="_.SecurityGetUser ()")"> I haven't gotten in to much of the details of python yet, so maybe I just need to get a little further along. The basic question is passing functions as arguments to a function. I hope that made some sense. Thanks Jeremiah