Setting a trigger to destroy an object

[MattTheJew]

I want to set two triggers on my map - one over the NATO base and the other over the Russian base.  I want it to act in the manner in which when an enemy unit enters this area the unit is destroyed.  I can't seem to get this to work.  
I tried using:
(thislist select 0) setdammage 1
but maybe I'm just being a jackass and missing something here.  I'd appreciate any help.

[macguba]

maybe its

" _x setdammage 1" foreach units thislist

or something.    You have to have the activation box set to the correct thing, say West present if you want to kill West units.