How to lose 15lbs fast?

I need to lose 15lbs fast! before I go back to school...
I want to know if walking and running will make me lose weight faster than pushups, squats, and situps???
im 16 140lbs 5'1 feet. want to be at healthy weight!
I can't always reach gym but I...

try to jumprope 10min at my house. I sit most of my day. I wake up like around 10am don't get hungry until after 12pm usually have some whole grain cereal with half a banana and a little organic soymilk
I then eat around 5-7pm again when I get hungry and start with a big salad with lots of veggie and beans and some chicken maybe some fruit later. if im still kinda hungry or maybe just craving something I eat a PBJ with a glass of milk. then wait until im sleepy which is always after midnight maybe even 2:30 am.

I need to sleep more and be a little more active to get hungry, be hungry at the right times and have control basically and don't know how. I want to have a routine and obviously burn more calories than I consume. I have a jumprope at home and two 4pound dumbells. I don't know what to do at the gym but walk and jog an hour on a trimill (however you spell it) . everytime I go, about 3 times a week.

I need advice on what to do. Tips. anything to help me reach my goal fast. please

Eat your breakfast within an hour of waking up. It's been proven that people who eat breakfast tend to be more lean than those who go without/eat it later. Breakfast kick starts your metabolism and gives your body fuel for the day ahead.

Source:
http://news.bbc.co.uk/2/hi/health/7275554.stm

If you have lots of sleep you will not get hungry, particularly if you woke up 10:AM, avoid sitting all day. You can clean your house or do some jobs that will get you tired. Disciplined in eating is number one way to lessen your weights, it's really difficult to loss fats. But you have to do it if you really like to lose weights, replace your old way of eating, if you can, choose water therapy, substitute for your snacks or breakfast. Milk is much good.

Your only 140 you are so lucky I am 17 and weigh 290 im over double your weight dont be worrying at least you can fit into jeans and other clothes