java script sleep synchronous

 function sleep(milliseconds) {
   var start = new Date().getTime();
   for (var i = 0; i < 1e7; i++) {
     if ((new Date().getTime() - start) > milliseconds){
       break;
     }
   }
 }

other version to see https://stackoverflow.com/questions/6484321/sleep-in-javascript-no-settimeout?noredirect=1&lq=1