Looking to make a age verifyer

still searching for a accurate age verify code. i have one but it is only for the year, it would be great if i could get one to the day. here is the code i have already to maybe give you a head start.

function verifyAge(userMonth:Number, userDay:Number, userYear:Number) {
var today_date:Date = new Date();
var month:Number = today_date.getDate();
var today:Number = today_date.getMonth();
var year:Number = today_date.getFullYear();
if (year-userYear<21) {
trace(“u too young”);

then you would pass input field values to the function:

on (release) {
verifyAge(‘09’, ‘26’, ‘1985’);

hope helps

any an all help would be great. here is a example of what i want to mimic