Trigger help plz.

Hi , like everyone else it seems I to am working on a RPG map :D
Well my question is: I want my monsters in a certain region
to respawn after X mins of play IF all monsters in that Unit
Group is dead. The respawned monsters goes to same
unit group as the dead ones and posibly keeps the item
drops defined for the old ones.

Got some of it to work but not all, also my way contained ALOT
of triggers :rolleyes: !!
Anyways thx for any help.