You have to lose the fat in your abdominal cavity. Thats all. Most likely will not happen in 30 days though. Depends a lot on how much deep belly fat you have. Sit ups and crunches arent all that necessary. Not til the fat is gone anyway.
Turns tucks tightens a dance workout that is just basically dancing with turning around abdominal area tucking chest in and tightening to keep stiff the traditional sit ups and curl ups work to but can take longer