[mod_python] Submitting a form with unknown number of items

Hi there, I can handle form data when I know how many items are 
returned.  I use a fixed number of parameters when someone signs up like:

def form_submit1(req,uname,passwd,passwd2,email,city,st,zip,country):
  ...
  ...
  ...

But when I have a varying number of form items (they are generated by 
data) I'm not sure how many there will be so how is that handled?  I 
tried to use "FieldStorage" as the only parameter (thinking it would be 
a list of form items) besides req but that doesn't work:

def buy_fromstore(req,FieldStorage):
  ...
  ...
  ...

How do you handle form data when you don't know how many items will be 
returned?

Thanks,
Jason Lanquist