Invader type game using a enemy controller

I have been trying for days to make this script but failed :(

what i want to do is control a set of emeneys individually so if one swoops the script will know that one is swooping and wont tell another one to untill that one is finished.

I also want the invaders to be fully controlled by the controller script like fire, move, swoop ect.

I have been told i can do this using enums and getcomponents.

What i would like is a example bit of code to issastrate how i can achive this.

Thanks

I think what you are looking for is a concept called a Finite State Machine.

http://ai-depot.com/FiniteStateMachines/

I would guess the enums being referred to are the different states and the components would be the actions for that state.