My sisters 89 Ford Probe wont run..see description below..

She left the lights on and killed the battery and when I charged it found there was no gas.(Ya I know bad news-You can choose your friends but not your family) I charged the battery and added gas and it started. At first it ran rough and an interesting symptom is it stalls when you put the automatic trans in forward. I did however back it up without stalling. Today it starts and immediatedly quits..it will start right back up easily but then quits.

Any thoughts of the possible causes based on these symptoms? I usually do all my own work but this is a different animal.

Appreciate guys,

Keith