I was at a stop and when I was about to step on the gas my
engine turned off..

There was another time where I was in my driveway, I was in park and
I put the shifter in reverse the engine turned off again

Im thinking maybe its because the Automatic Transmission
needs oil because my Transmission leaked oil because
I removed one time the oil dipstick tube to remove a part and it leaked alot of oil so I put the oil dipstick tube back in its place..

I checked the Transmission oil level on Jan-18-2011 and it was low..Im wondering maybe its the reason why my Cavalier shut off at a stop
and in my driveway

Can someone help me??