2048 keys in circle moves

2048-circle.js

function mouseEvent(type, sx, sy, cx, cy) {
  var evt;
  var e = {
    bubbles: true,
    cancelable: (type != "mousemove"),
    view: window,
    detail: 0,
    screenX: sx, 
    screenY: sy,
    clientX: cx, 
    clientY: cy,
    ctrlKey: false,
    altKey: false,
    shiftKey: false,
    metaKey: false,
    button: 0,
    relatedTarget: undefined
  };
  if (typeof( document.createEvent ) == "function") {
    evt = document.createEvent("MouseEvents");
    evt.initMouseEvent(type, 
      e.bubbles, e.cancelable, e.view, e.detail,
      e.screenX, e.screenY, e.clientX, e.clientY,
      e.ctrlKey, e.altKey, e.shiftKey, e.metaKey,
      e.button, document.body.parentNode);
  } else if (document.createEventObject) {
    evt = document.createEventObject();
    for (prop in e) {
    evt[prop] = e[prop];
  }
    evt.button = { 0:1, 1:4, 2:2 }[evt.button] || evt.button;
  }
  return evt;
}
function dispatchEvent (el, evt) {
  if (el.dispatchEvent) {
    el.dispatchEvent(evt);
  } else if (el.fireEvent) {
    el.fireEvent('on' + type, evt);
  }
  return evt;
}
function fireKey(el, key)
{
    if(document.createEventObject)
    {
        var eventObj = document.createEventObject();
        eventObj.keyCode = 37; // left
        el.fireEvent("onkeydown", eventObj);   
    }else if(document.createEvent)
    {
        var eventObj = document.createEvent("Events");
        eventObj.initEvent("keydown", true, true);
        eventObj.which = key;
        el.dispatchEvent(eventObj);
    }
} 
 
function action ()
{
    fireKey(document, 37);
    fireKey(document, 38);
    fireKey(document, 39);
    fireKey(document, 40);
    var t = document.getElementsByClassName("game-over")[0];
    if (t != undefined) {
        var evt = mouseEvent("click", 1, 50, 1, 50);
        dispatchEvent(document.getElementsByClassName("retry-button")[0], evt);
    }
}
 
setInterval(action, 200);