Character Counts / timeout

The code

(function () {
  var div, txt, timer;
  div = document.getElementById('charcount');
  txt = document.getElementById('inputfield');
  txt.onkeyup = function () {
    clearTimeout(timer);
    timer = setTimeout(function () {
      div.innerHTML = txt.value.length;
    }, 10);
  };
  txt.focus();
})();