Infinite loop (with a delay) or an OnCast event

[isiz]

So I am trying to create a mod for the first time. Basically what it will do is wait for a certain spell to be cast by the user and then announce a message in chat. What I need to know is how I would go about looking for the spell to be cast. Currently I have it checking for the cooldown to be at max (120 secs or 2 min) and then announcing, but I think all it will do is look for the cooldown as you log in and then cease operation.

I need a way to constantly look for whether this spell has been cast. Perhaps an infinite loop, but with a delay of say, .5secs so as to not overclock your computer. It would also be nice to instead of looking for the cooldown to look for the spell being cast (maybe in the combat log?). I could not find anything in the API function page on Wowwiki that would let me do that. Would it be a complex function that I have to create myself?

[_Chloe]

Get a CLUE

http://www.wowwiki.com/API_COMBAT_LOG_EVENT

Note: It's called CLUE - Combat Log Unfiltered Event