javascript - Correct time calculations for XMLHttpRequest -

To get the calculations in Chrome WebRest, I am using the code below, below are the prices I

  request.addEventListener ("readystatechange", function () {var time = date.now (); // would like to be calculated as this.startedDateTime when it is sent; (switch.) (Case: (new date ()). (),;; 2; this; _ $ connect = time; this._send = (time - (new date) (this. Starreddeterm)). GetTime ()); this. _connect = (time - (new date (this. Start date time)) Gettime ()); break; case 3: this._ wait = time - connect it ._ $; it ._ $ wait = time; break; case 4: this. _receive = (time - this ._ $ wait) || 0; it._time = (time - (new date (this start date) .gettime ())); break;;});  

But when I debug it, it does not look right. How can I change to work properly?