DarkRP Job when other job is taken

Hello, I currently have these jobs: Osama Bin Laden and Terrorist, How can I do so, when there is no osama bin laden, noone can go terrorist? And so it creates a hint saying: “this job will be unlocked as soon as there is an Osama”

I’m making Osama bin laden donator only, cause it has some rules attached to it, people are abusing it at the moment.

thank you!