98 Malibu cruise control problems

My cruise control has recently quit on me.:banghead: I can push the on/off button on my steering wheel and the light comes on as though it is on. When I push the button to set my speed, the light comes on saying cruise control. But it doesn't hold my speed. Any one have any suggestions on what to look for or test or fix. I drive alot of miles during the week and cruise always made it more comfortable for me. I have searched the web time and time again, but have come up emply handed. Help me PLEEZ!!!