Quick question about mass killing through triggers

Ok herez the deal. A Villager steps on a circle of power (i have set the regions and stuff like that) then all the units within another area die. can some one help me with this cause therez gonna be a mass of em that i need to kill off and i have to do it by triggers. also the units arent already in the map that i need to kill.

thanks ahead of time cause i have no idea how todo this one with the given options within the w3editor

a starcraft version of this trigger would be:

event:
-unit enters <region>

action
-kill all units of <type> within <region>

maybe that would help clear things up. thanks again

Its basicly the same thing. Keep in mind that killing units like this will not give gold or exp.

Events
Unit - A unit enters Enter Region <gen>
Conditions
Actions
Unit Group - Pick every unit in (Units in Kill Region <gen>) and do (Actions)
Loop - Actions
Unit - Kill (Picked unit)

E: A unit enters XX region
C: Entering Unit = YY unit
A: Unit Group - pick all units in (XX2 region) and do action kill (picked unit)

i forgot about the picked unit function lol thanx to both posts :)

wow... i feel really stupid now

ok therez the trigger that i used if ne one else wan't it

Unit Group - Pick every unit in (Units in Mustard Gas Kill <gen> matching ((Unit-type of (Matching unit)) Equal to Marine)) and do (Unit - Kill (Picked unit))

thanks again