Hi YangYang,
You may want to hire a personal trainer to come to your gym one day with you and give you some advice. Doesn't cost much and is worth the $ in my opinion.
But, for the price of asking, I'll give you a bit of advice on your workout: Increase your cardio to 30 min. using whatever machine you want. I prefer the elliptical trainer because it's very low impact and works both upper and lower body. But walking on the treadmill is also great and very low impact. So, whether it's bicycle, treadmill, stair climber, aerobics class, whatever... try to do at least 30 min five days a week to improve your heart and general health.
What really helps get rid of the flabby areas is strength training. Ideally, you should probably be doing 3 sets of 8-13 reps with weights set such that the last rep of each set is very difficult to do (not impossible, but difficult). 8 machines may not be working all muscle areas. A personal trainer (or maybe one of your friends) could show you weight exercises that could be done with free weights (barbells and dumbells) to augment the machines. You should be giving muscle groups at least 48 hours between workouts. So you could work arms, shoulders and back one day and legs another day. Don't forget to do your sit-ups for your abdominal muscles. And you should stretch before and after strength training.
Here's what my workout schedule looks like:
Sun: 30 min cardio, stretch, arms, shoulders, back, abdominal, stretch
Mon: 30 min cardio, stretch, legs, abdominal, stretch
Tue: 45 min cardio
Wed: 30 min cardio, stretch, arms, shoulders, back, abdominal, stretch
Thur: 30 min cardio, stretch, legs, abdominal, stretch
Fri: 45 min cardio
Sat: No workout
What can you expect? If keep it up, you will build muscle which is more dense than fat, so you'll have a firmer (and smaller) body. Also, if you're still trying to lose weight, you'll lose it faster as your metabolism increases. If your just trying to maintain your weight, you may need to eat a few more healthy snacks to supply the calories you need for your workouts.
I hope this helps!
EthansMom