Top down / 8 Directions Jumping

So I am making a Top Down Zelda Clone (what's new??) using custom movement. I have my collisions working just fine, but now I wanted to add a jumping ability for the player. does anyone know of a method that would easily accomplish this. All the help will be greatly appreciated.

Check out this tutorial.

http://reinerstileset.4players.de/TUTjumpengine3d.zip

good luck!

Hmm I only seem to be able to jump once using this, then it doesn't let me jump again : S

Magicians Lair doe's this, have a look at it.