Ricardo
To extend a class or implement an interface in an anonymous you would use code similar to this:
in this case your creating a new anonymous class that implements the ActionListener interface. There is no class name (that's why they are called anonymous). You just supply the name of the class or interface you are extending or implementing. That's why in anonymous classes you can only extend one class or implement one interface.
hope that helps
Dave
for more details, check this out:
http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#252986