[Zope] How to write a method using DTML Method?

[Guy Davis]

How would I convert the following Java code into DTML?  This is just an
example, I don't understand how methods are used in DTML.

String getFirstName(String name) {
   String lastName = name.substring(0, name.indexOf(' '));
   return (lastName);
} 

I would like to see a DTML method which does this, how it is called and
how the result is used in the calling method.  Thanks.
-- 
       Guy Davis    mailto:davis@arc.ab.ca
  (403) 210-5334    Alberta Research Council