var btnOne = document.querySelector('#btnOne'),

    btnTwo = document.querySelector('#btnTwo'),

    output = document.querySelector('output');

​

btnOne.addEventListener('click', function() {

  alert('button 1 clicked');

}, false);

​

btnTwo.addEventListener('click', function() {

  alert('button 2 clicked');

}, false);

​

var el = document.getElementById('body'),

    elClone = el.cloneNode(true);

​

el.parentNode.replaceChild(elClone, el);