Abs Help

[new2weights]

I currently work my abs once a day usually doing knee ups while hanging from a chinup bar. I do 5 sets and get about 15 reps per set on an average day. I also use the eliptical machine for 30 min after each workout to help burn fat. I am 5 11 and currently down to 162 from 175 and now my results seem to be tapering off. I was going to add another ab exercise each day is there anything else that would help such as sprints instead of cardio or should i just do 30 min of cardio a day? Also i hear that using a fat loss supplement could help and i was wandering if it would help me lose the last 5- 10 pounds i need to lose to fully see my abs? Im only 18 though and was wandering if a product like that would work for some one my age. Any suggestions on exercises or supplements would help.

[new2weights]

Also to add i am basically sure that if i would lose fat around my mid section that i would have a six pack because my abs feel pretty strong its just that they are covered up by fat, especially my lower abs in particular.