In Team fortress 2 how to make yourself invisible with the apple mouse

This is the biggest problem when playing TF2 on a mac, the Macintosh mouse has only one button on it (a bit odd if you ask me). There are 2 solutions:

1. Buy a normal mouse.
2. Go to options->keyboard and scroll down to Team Fortress 2, you'll see how all of the button assignments for things like "spin minigun", "activate ubercharge", "cloak" etc. are missing. Assign a button for them.