[Zope] Newbie: need a simple example of external method

[Hung Jung Lu]

Hi,

I just subscribed to the mailing list, and in less than one 
day I got 60 messages, wow! This list surely is active.

Can anyone give to me a simple example of a DTML
document calling an external method? I mean, if I
have a Python program

myprogram.py:

def myfunc(x):
    return 2*x;

How do I proceed to use it in DTML, and how do I 
place it in the external methods folder?

regards,

Hung Jung