Depending on how fit you are.. jog 30-40 mins, 4-5 times a week.
Train your abs 2-3 times a week, depending on how quick they recover. (Don't do situps... do crunches, captains chairs', reverse crunches etc...)
Good luck, if your eating right, and training right, depending on how fit you are, expect good results in 2-3 months.