You should also include exercises targeting the area that you want to loose fat from.  When you exercise a specific area the amount of blood flow is massively increased to that area.

Energy is also sapped from the area were the specific exercise is targeting and this means that the blood flow will tend to use fat from that region.

Sit ups and crunches are a great fat burning and abdomen tightening exercise for the mid section region.  I would advise that you include these along with various forms of aerobic
exercise such as running, swimming and cycling.