var trigger = document.getElementById('trigger');
var close 	= document.getElementById('close');
var modal 	= document.getElementById('modal');

trigger.onclick = function() {
  modal.classList.add('open');
  var overlay = document.createElement('div');
	overlay.classList.add('overlay');
  overlay.id = 'overlay';
  document.body.appendChild(overlay);
}

close.onclick = function() {	   
  modal.classList.remove('open');
  document.body.removeChild(overlay);
}