How do I lose the big tummy?

So I am a very big girl, 350lb, and I have been working out alot since feb and my diet is at a good stage, but I cant seem to get any results in my tummy area!! I was wondering if doing sit ups will be best, or I dont know, those yoga balls people do crunchs on, Im not sure, I just really really want to start to lose the big belly, any advice on whats best to eat so it can burn off qicker, and what exercises makes the tummy slim down? I go on the ellipical trainer for 45 mins and do free weights, and want to start doing more to work on the problem areas, thanks!!

I found a few things that might help you out. and your doing fine. Keep it up.

Lose 5lbs in a week:
http://fitandhealthyliving.blogspot.com/2008/06/lose-5-pounds-in-week.html
Lose 5-10lbs fast:
http://fitandhealthyliving.blogspot.com/2008/06/lose-5-10-pounds-fast.html
Proactol Natural Weight Loss Diet Aid:
http://fitandhealthyliving.blogspot.com/2008/06/proactol-natural-weight-loss-review.html

Slimming Down with Stevie: Maximum Wii Fit