driving to work this morning in my 99 540i, I noticed that the DSC and ABS lights lit up on the display whenever I had the car in gear and giving it gas. when I was at a stop light and idling, the lights would go off. after coming back to my car in the afternoon after a day at work, the battery was completely discharged. remote unlock didn't work, no lights, nothing. I jumped it with the aid of another car, and it seemed fine. I drove it home and no DSC lights or ABS came on this time. after the 10 minute drive home, i shut the car off, then tried it again, and it started. This time the battery light came on, and stayed on. I drove it on my street, no more than 1/10 of a mile, and the DSC and ABS lights started doing the same thing (they lit up when in gear and accelerating, and turn off when idling). any ideas on what the issue could be? alternator? battery? thanks in advance for any assistance.