Need help with a direct damage/slow hero ability

First off, I am not a complete n00b. I know how to do a lot of things in the World Editor, so you need not explain them to me, however, if it involves anything outside the world editor (such as extracting .slk files) you may need to give a little explanation.

Now, this is my problem - I'm trying to create a Frostbite spell which deals direct damage to an enemy unit and slows them down for a few seconds. It's a hero ability with 3 levels, with the following desired stats -

Level 1 - 100 damage, slows 60% for 15 seconds.
Level 2 - 200 damage, slows 70% for 20 seconds.
Level 3 - 400 damage, slows 80% for 30 seconds.

Now, the thing is, I can't seem to get this to work in the World Editor. Granted, I'm not the best at spell editing, and I freaking hate triggers, considering that I already tried using triggers to add the slow effect, but to no effect. I may have to do some JASS editing, I don't know, but that's one of the things that I have absolutely no experience in.

Anyway, basically I just want to know how to do this... it would be extremely helpful. Thanks.

EDIT - Turns out I am a complete n00b. Disregard this, I figured out how to do it... wow, I'm stupid :P