If you're looking to get a flat stomach in only 2 weeks, you're going to have to drop everything and launch a full out assault on body fat. It's possible to lose a lot of weight in this short period of time, but I wont lie to you, you're going to have to work a little. In this article I'll give you some strategies for losing the belly fat quick.
The first thing you should do is get yourself on a very low carbohydrate diet. The main source of your carbs should come from green vegetables. You should try to eat 4-6 smaller meals throughout the day, each containing protein and healthy fats such as almonds or avocado. One meal a week you should cheat. Meaning eat whatever you've been craving. This will restore your glycogen stores (which will be depleted from the lack of carbs) and actually aide in helping you lose fat.
Next you're going to want to walk in the morning upon waking up and on an empty stomach. Ideally, you'll do this on a treadmill with an incline of at least 8%. You want to get a sweat going but this shouldn't be a full on workout. Steady walking like this has been shown to shed faster than even running. And it's much easier to stick with.
You might also consider starting a workout program that includes complex movements such as deadlifts. These types of exercises will burn more calories and actually work your stomach muscles better than crunches can.
All this stuff might sound a lot harder than it really is. There's no reason why you can't lose a significant amount of weight and get a flatter stomach in 2 weeks using these strategies.