docs: function pollDo(fn, timeOut, doName, obj) {
    var siv = null;
  
    if (!obj) {
      obj = window;
    }
    if (timeOut == null) {
      timeOut = 100;
    }
  
    //If the previous poll operation is exist,then make it cancel.
    if (doName && obj[doName]) {
      clearInterval(obj[doName]);
    }
  
    //Polling execution operations every interval a period of time.
    siv = setInterval(function () {
      if (fn.call(obj) === false) {
        clearInterval(siv);
      }
    }, timeOut);
  
    if (doName) {
      obj[doName] = siv;
    }
  
    return siv;
  }