How do I rotate a character with my mouse?

ok so Ive done it before, just cant remember how:

how do I make the character turn left when you move the mouse left, right and so forth, with the character facing away from the camera. How would I do this? I think theres already something that lets you, I just cant remember :)

If you go to component > Camera-Control > Mouse Look script:

put that on your character and then change the min and max value of Y to 0 to stop him looking up (only if this is what you want, that will make him look left and right but not up and down)