Location/directions to fill clutch fluid? on 1999 Chevrolet Cavalier

I just felt my clutch lose pressure in the past few days and I'm assuming that's because the fluid is low. However, I'm not sure where the spot is to fill it, what to put in it, etc.

Thanks in advance.

Asked by for the 1999 Chevrolet Cavalier
Next to (near) the brake master cylinder, there should be a small, round, white reservoir with a black twist off cap, it takes brake fluid also!!
Owners manual is a must for any car owner/driver!! This info. is in there. Probably with pictures too!!!