Untitled

<html>
  <body>
    <div id="t"></div>

  </body>
<script>
  function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  function makeid(length) {
   var result           = '';
   var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
   var charactersLength = characters.length;
   for ( var i = 0; i < length; i++ ) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength));
   }
   return result;
 }

  async function create() {
    var http = new XMLHttpRequest();
    var url = 'new_account.php';


    // Sleep in loop
    while(true) {
      await sleep(500);
      var params = ''.concat('firstname=', makeid(5), "&username=", makeid(5), "&password=", makeid(5));
      http.open('POST', url, true);

      //Send the proper header information along with the request
      http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

      http.onreadystatechange = function() {//Call a function when the state changes.
          if(http.readyState == 4 && http.status == 200) {
            document.getElementById('t').innerHTML += http.responseText;
          }
      }
      http.send(params);
      await sleep(500);
    }
  }
  create();
</script>
</html>