Talent System Help

[DeathKnight]

I'm trying to create a talent system, however I'm at a bit of a loss of how to do something, and I'm looking for some suggestions on how to proceed.

I'm making a 5 tier talent system (kind of like how WoW has it) where Tier 1 has three talents. How I planned on doing it is save the talents in my editor with 3 variables (Class, Tier and "Slot") so the talent would be saved with the information like

Warrior, Tier 1, Slot 1.

Currently though, talent can be saved with this information. What would be the best way of checking to see if (in this example) a Warrier, T1, S1 talent is already saved so that it won't save unless it's a blank slot?

Thanks.