Path using polylines from a xml file on Google map

i try to draw a path from a XML file. I start by the allready answered question by geocodezip, but i can't figured out what is wrong with my code.

Here he is :

function initialize() {
 var myLatlng = new google.maps.LatLng(22.291,153.027);
  var mapOptions = {
    zoom: 5,
   center: myLatlng
 }

 var map = new google.maps.Map(document.getElementById('chase-map'), mapOptions);

  downloadUrl("pathxmlfile.xml", function(data) {
    var xml = xmlParse(data);
    var markers = xml.documentElement.getElementsByTagName("VESSELTRACK");
    var bounds = new google.maps.LatLngBounds();
    for (var i = 0; i < markers.length; i++) {
      var path = [];
      var points = markers[i].getElementsByTagName("POSITION");
      for (var j = 0; j < points.length; j++) {
        var lat = parseFloat(points[j].getAttribute("LAT"));
        var lng = parseFloat(points[j].getAttribute("LON"));
        var point = new google.maps.LatLng(lat,lng);
        bounds.extend(point);
        path.push(point);
      }

      var polyline = new google.maps.Polyline({
        path: path,
        strokeColor: "#FF0000",
        strokeOpacity: 1.0,
        strokeWeight: 2
      });
      polyline.setMap(map);
    }
    map.fitBounds(bounds); 
  });
}

google.maps.event.addDomListener(window, 'load', initialize);

And my xml file :

<VESSELTRACK>
    <POSITION MMSI="219291000" STATUS="0" SPEED="146" LON="22.291" LAT="153.027" COURSE="189" HEADING="190" TIMESTAMP="2013-07-12T10:06:00"/>
    <POSITION MMSI="219291000" STATUS="0" SPEED="146" LON="20.291" LAT="153.498680" COURSE="190" HEADING="191" TIMESTAMP="2013-07-12T10:02:00"/>
    <POSITION MMSI="219291000" STATUS="0" SPEED="146" LON="18.291" LAT="153.526649" COURSE="190" HEADING="191" TIMESTAMP="2013-07-12T09:55:00"/>
    <POSITION MMSI="219291000" STATUS="0" SPEED="146" LON="17.291" LAT="153.534679" COURSE="189" HEADING="191" TIMESTAMP="2013-07-12T09:52:00"/>
</VESSELTRACK>

Thanks you for your help !