battery 2

today when driving to school i turned on my air and my rmp gauge get down with my speedometer and my check engine flashed and then my the gauges went back on then when i got to school i shut off my car then i tryed to turn it back on and my batter was died then my friend jumped me and it started back up. then i shut it off and it started agian. but the battery still could be dead. can someone help me i have a 94 probe