Thread: [SOLVED] Cases

I want to define a function so that even numbers will go somewhere and odd numbers will go somewhere else. How would I get LaTeX to do the curly bracket needed, one that has two rows?

What I want to do is which looks fine. However...I can't put it in my document! It doesn't like the "&"s, and does nothing if I take them out...It's in a "\newtheorem{answer}{Answer}...\begin{answer}...\e nd{answer}" thingy if that makes any difference?

Help?

Anyone? It is not liking the alignment tab character...

EDIT: Nevermind - I thought I was using amsmath when actually I hadn't loaded it. oops.