Calculate age

HTML

<form action="#" method="post" id="age">
    <label for="birthday">Birthday (yyyy-mm-dd)
        <input type="text" name="birthday" id="birthday" />
    </label>
    <input type="submit" name="submit" value="Calculate your age"/>
</form>

JavaScript

var calculateAge = function(birthday) {
    var now = new Date();
    var past = new Date(birthday);
    var nowYear = now.getFullYear();
    var pastYear = past.getFullYear();
    var age = nowYear - pastYear;
		alert(nowYear);
    return age;
};

$('#age').submit(function(e) {
    e.preventDefault();
    var $birthday = $('#birthday').val();
    alert('Aakanksha is ' + calculateAge($birthday) + ' years old');
});