ion(el) {
        el.innerHTML = 'my-div-2';
      });
     
      // add a new div to the DOM
      function addDiv() {
        var el;

        // add instance of my-div-1
        el = document.createElement('div');
        el.className = 'my-div-1';
        document.body.appendChild(el);

        // add instance of my-div-2
        el = document.createElement('div');
        el.className = 'my-div-2';
        el.style.display = 'none';
        document.body.appendChild(el);        
      }

      // togg