基本上我想在“numYear”輸入我的出生日期，但它沒有得到值。這是我的代碼：function myAge() {    let myBirthYear = document.getElementById('numYear').Value;    let result = (2020 - myBirthYear);    //create h1 element    let h1 = document.createElement('h1');    let h1elem = document.createElement('class','newelem');    let answer = document.createTextNode('You are ' + result + ' years old!');    h1.appendChild(answer);    document.getElementById('results').appendChild(h1);}