var input = document.getElementById('date');
var result = document.getElementById('result');
input.onchange = getAge;
getAge();
function getAge() {
var strDate = document.getElementById('date').value;
var arrDate = strDate.split(/\D+/g);
var date = new Date(arrDate[2], arrDate[1] - 1, arrDate[0]);
var now = new Date();
var age = now.getFullYear() - date.getFullYear();
now.setFullYear(date.getFullYear());
if (now < date) age--;
result.innerHTML = age+' лет';
}
