Killing a function on certain condition?

programming flash
1

Ive always wondered how to do this because functions rock but they cause me so much pain due to how I use them.

For example. Say we’re driving a ship at a constant rate of 45 miles per second:

function milesTraveled() {
	myMiles += 45;
	if (myMiles>=4500) {
		myMiles = 4500;
		trace("reached destination");
		refillGas();
	}
}
setInterval(milesTraveled, 1000);

Now as you can see it runs the function refilllGas(); but it -keeps- on running refillGas(); due to the setInterval that runs the main function everysecond.

Any way to cut the function milesTraveled for good once I hit a certain condition?