Ford Escort check engine light on and off and car stalled out while driving.

The check engine light on my car goes on and off. I was driving it and while on a busy road the car just stalled. I was able to put my hazards on and they blinked just fine. I originally thought it was the battery so some good Samaritan stopped by with jumper cables and when we hooked it up and I started the car it wouldn't start but the battery is ok. I do not think it was the alternator because the hazard lights came on. Couldn't get it to start and had it towed back to my apartment.