Ruby-like Question: Make this function shorter (ActionScript 3)

Question

I just wrote this incredibly verbose code to turn numbers like 2 into 02. Can you make this function shorter, please (maintaning the functionality)?

Answer 1

private function leadingZeros(value:int, numDigits:int):String
{
            return String(new Array(numDigits + 1).join("0") + String(value)).substr(-numDigits, numDigits);
}