How to give users shutdown privileges?

I want to give a few normal users (non admin) the ability to shutdown and restart my servers after normal working hours. Ive created an account in User Manager(NT4 terminal server) and they can log in but when they select shutdown and restart theyare told they do not have the proper permissions. Ive went into user manager policy's for that account and it shows they are added for shutdown function. How come they can do it?