Trigger Help!!

I need to make a trigger where if a unit comes within meelee range of a unit, he dies. But I have several units that i want to do this with, all in one trigger. Is this possible, or do i have to do it with multiple events?

There will be less lag in your map if you make speical triggers for each character or character type.

Otherwise it will check every unit every time.

what special triggers...? (I'm still a trigger noob :))