Addon doors

Hi,

i am french men, sorry for my bad english <:

I need a plugin, and a think he exist.

Exemple :

You play on a darkRP server, and he as got a arms dealer selling gun to civilization.

5 minutes later, arms dealer disconnect.

I have on my map, a appartment, and i need it's open ONLY if arms dealer is offline.

it's possible ?

thanks max