Thank you everyone, but I still not understand why such a comon feature like passing parameters byref that is present in most serious programming languages is not possible in a clean way,here in python.
I have the habit to never use globals as far as possible and this involve that my main function is passing some parameters by reference to subs to allow them to modify the vars. I would be sad to break my structured programming scheme because a lack of feature. In others languages you can use things like pointers to strings or Mysub(byref MyVar) .... and it does the trick :) -- http://mail.python.org/mailman/listinfo/python-list