How do you fix this NPC destruction script?

I have an NPC, and im trying to create a script that will destroy it after 3 seconds. This is what I have, and there are no errors shown, but it isn't working:

function player(NPC) local NPChealth = 100 local NPCspeed = 15 local GroupAnchored = true local GroupGrouped = true

end

script.wait(3) local GroupAnchored = false local GroupGrouped = false