What script do I use to make it so if you kill friendlys they will turn back at you.

It's in the hs_doc. Take a look at it sometime.
use commands like ai_alligience, and ai_alligience_broken to test it.

i think in general though if you kill enough they automatically turn on you.

They don't, I killed hundreds of them in my single player map i'm making and they don't turn.

oh then just try slappy's way, his should work.

That's the method employed in the campaign. Set them on a different team, and ally them to the player through the use of ai_allegiance.

Ok but what do I do so it does it when I kill them. Because it seems like if the other ai kill them they will turn on me without me doing it. Unless the script only applies to the player.

I don't think you understand the purpose of the command. Basically, you put the "friendly AI" on another team, such as human. They will inherently be your enemies. However, when you use the ai_allegiance command, in the form of:
(ai_allegiance player human)
thus creating an allegiance between the player and everyone on the human team, then they will be actual friendlies. However, when you "betray" the alliance, then the alliance will break, and they will turn against you.

Ok I get it now but one more thing. Why is it saying False when I put in "ai_allegiance_broken player human" for sapien's console?

ai_allegiance_broken is a boolean command, which returns whether the two teams have broken their allegiance or not. If it says false, that means that the player and human teams are still allied. If it says true, then that means that they aren't. It's not a command that does something; rather, it's a "getter" command: one that returns a certain value.

Note to Gamma: Gamma get on xfire