Answers for "how to add role to an new element created javascript"

create element javascript with id

var btn = document.createElement('div'); 
btn.setAttribute("id", "div1");

javascript document.createElement add function

var newTH = document.createElement('th');
newTH.innerHTML = 'Hello, World!';
newTH.onclick = function () {
    this.parentElement.removeChild(this);
};

var table = document.getElementById('content');
table.appendChild(newTH);