Simple problem?

thats why I have written this proggy

- what I dont understand:
If defined before, this var should be used?
If not defined, it should be set!
Returning should always work?!

So please tell me why it doesnt work (what is is doing exactly, and how it
should be done (not using @xx or @xx or $xx) - i did this to see how Ruby
is working.

Thx Berg