Var click = document.getElementById('click');
var textarea = document.getElementById('textarea');
var clicks = document.getElementById('count');
var dcCount = document.getElementById('dcCount');
var reset = document.getElementById('reset');
reset.onclick = function() {
  clicks.value = 0;
  dcCount.value = 0;
  textarea.value = '';
  click.style.background = 'orange';
}

var prevClickMicrotime = microtime(true);
function microtime(get_as_float) {
  var now = new Date()
    .getTime() / 1000;
  var s = parseInt(now, 10);

  return (get_as_float) ? Now : (Math.round((now - s) * 1000) / 1000) + ' ' + s;
}

var prevClickMicrotime = microtime(true);

function clickEvent() {
    clickTime = microtime(true);
  diff = clickTime - prevClickMicrotime;
  var d = Math.random();
if (d <= 0.7) //this is 70%
{
    click.style.background = 'red';
    dcCount.value++;
}
  textarea.value = diff + "\n" + textarea.value;
  prevClickMicrotime = clickTime;
  clicks.value++;
}

function mouseClick() {
    var e = window.event;
      console.log(e);
      clickEvent();
    return false;
}