auto boxes are a pain, if you took the oil out of it, you will need to start the car and keeping the hand brake on go though the gears 1 at a time to allow fluid to settle thougout gear box. you might need to have a word with a mechanic for more advise, try one of the smaller "one man band" type as these tend to give the right advise more freely.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.