Inserting commas into numbers (SOLVED)

I’d like to have commas every three digits in my score display to make it easier to read. I had this problem once before, in my AS2 days, and I solved it by seperating each digit of the number and then arranging the number like so:

ten thousands digit, thousands digit, comma, hundreds digit, tens digit, ones digit.

Obviously that’s a lot of excessive code.

I know that I can turn my score to a string, work out how many characters there are in the string, and then insert the comma in between characters 2 and 3 for example.

But I don’t know what the functions are that I need to use. Can someone please tell me what they are?
-Yoshiyahu

PS. Unless someone already has an algorithm I can steal that calculates it for me, without an if statement for every possible number of digits.

this issue came up many years ago, i and another programmer got into a performance war over it and this was my final result:

		final protected function numberDelimiter2(num:Number, decimalPrecision:int = 0, delimiter:String = ",", charGroup:uint = 3):String {
			var d:String = num.toFixed(decimalPrecision);
			if (int(charGroup == 0) | charGroup >> 31) return d;
			var n:int = int(num < 0), len:int = d.length - n - (decimalPrecision + int(decimalPrecision > 0));
			if (len <= charGroup) return d;
			if (len % charGroup) {
				var c:int = n + len % charGroup, o:String = d.substring(0, c);
				while (~(((len -= charGroup) >> 31))) {
					o = o + delimiter + d.substring(c, c += charGroup);
				}
				return o + d.substring(c);
			}
			var count:int = n + charGroup, out:String = d.substring(0, count);
			while (len -= charGroup) {
				out = out + delimiter + d.substring(count, count += charGroup);
			}
			return out + d.substring(count);
		}

i could improve its performance substantially by using a ByteArray, but it won’t be used often enough to warrant that

Thanks again mate, works perfectly!