AJAX request se sám odpojí

function Streamer(ip,port) {
  var http = null;
  var buffer = "";
  var seeker = 0;
  var _this=this;
  this.ip = ip;
  this.port=port;
  this.start = function() {
    http=new HTTPRequest();
    http.open("GET", "http://"+this.ip+(this.port!=""?":"+this.port:""), true);
    http.onreadystatechange = readdata;
    http.send(null);
  }
  this.restart = function() {
    http.abort();
    http=null;
    seeker=0;
    buffer="";
    setTimeout(function() {_this.start();},500);
  }
  this.ondata = function(data) {console.log(data)};
  function readdata() {
      if(this.readyState==3||this.readyState==4) {
          seektmp = seeker;
          while(seektmp<this.responseText.length) {
                      /*parsování*/
             }   
      }  
     if(this.readyState==4) {
        _this.restart(); 
      }
    }
}