Hyundai Repair: 1999 hyundai elantra, rear window defogger, hyundai elantra

Question
my clock light went dim and my air bag light came on could this be my battery or alternator

Answer
If this happened while you were driving, the issue is most likely that your alternator has stopped charging.  If that's the case, and you keep driving, you'll eventually drain the battery to where it doesn't have enough power to keep the car running.  This will happen in a short period of time if you're operating the heater or a/c, the headlamps, the rear window defogger, or the wipers.