var addRow = document.getElementById('addRow');

​

(function(){

  var text = '';

for(var i = 1; i<= 2; i++) {

    text += "<div class='row'>";

    for(var j = 1; j<= 3; j++) {

        //createNode();

        text += "<input type='text' readOnly/>";

    }

    text += "<br>";

    text += "</div>";

}  

  sheet.innerHTML = text;

})();

​

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

    var rows = document.querySelectorAll('.row');

    var dupNode = rows[0].cloneNode(true);

    sheet.appendChild(dupNode);

}, false);

​

var inputs = document.getElementsByTagName('input');

for(var i = 0; i <= inputs.length - 1; i++) {

    inputs[i].addEventListener('click', function(){

      alert("clicked");

    }, false);

}