[Zope] ZClass-Inheritance Problem

Hi there... i have a ZClass (name: class1) and another ZClass (name: class2) which inherits from class1. Class1 has a dtml-method called doSomething(). Instances of class2 are supposed to use this method in an extended way which would look like this: <dtml-comment>doSomethingMethod of class2</dtml-comment> <dtml-call doSomethingOfClass1> <dtml-call doSomethingElse> My question is: how can I make a method of class2 call its parents method? Thanks Falk