i cant find a tutorial about this in halomaps.org
Someone can help me? the only thing that i know is that i have to make a script.

You place a trigger volume, then adjust the size to fit the area you desire.

Here's a script that should work. Change "trigger_volume" to the name of your trigger volume.

(global short plr 0)

(script continuous kill_volume
  (if (volume_test_object "trigger_volume" (list_get (players) plr))
    (unit_kill (unit (list_get (players) plr)))
  )
  (if (= plr 15)
    (set plr 0)
    (set plr (+ plr 1))
  )
)

thanks very much... this is exactly what im looking for