//Create marker and set up event window
  function createMarker(point,html){
        var marker = new GMarker(point);
        GEvent.addListener(marker, "mouseover", function() {
            marker.openInfoWindowHtml(html);
        });
        return marker;
  }


function load() {
    if (GBrowserIsCompatible()) {
           var map = new GMap2(document.getElementById("map_canvas"));
        map.setCenter(new GLatLng(52.302391,4.766693), 12);
        map.setUIToDefault();

        map.addControl(new GMapTypeControl());

       GDownloadUrl("/xml/companies.php", function(data, responseCode) {
          var xml = google.maps.Xml.parse(data);
          var markers = xml.documentElement.getElementsByTagName("marker");
          for (var i = 0; i < markers.length; i++) {
            var point = new GLatLng(parseFloat(markers[i].getAttribute("lat")),
                              parseFloat(markers[i].getAttribute("lng")));
            var html = markers[i].getAttribute("html");

            var marker = createMarker(point,html);

            map.addOverlay(marker);

          }
        }
        );

   }
}

function initialize(id) {
  if (GBrowserIsCompatible()) {
    var map = new GMap2(document.getElementById("map_canvas"));
    map.addControl(new GMapTypeControl());
    map.setCenter(new GLatLng(52.302391,4.766693), 11);
    map.setUIToDefault();

    //create randomnumber and retrieve xml file
    var randomnumber=Math.floor(Math.random()*11111)
    GDownloadUrl("/xml/companies.php?id="+id, function(data, responseCode) {
    var xml = GXml.parse(data);

    //store markers in markers array
    var markers = xml.documentElement.getElementsByTagName("marker");

    //loop over the markers array
    for (var i = 0; i < markers.length; i++) {
        var lat = parseFloat(markers[i].getAttribute("lat"));
        var lng = parseFloat(markers[i].getAttribute("lng"));
        var point = new GLatLng(lat,lng);
        var html = markers[i].getAttribute("html");
        var marker = createMarker(point,html);
        map.addOverlay(marker);
    } //close for loop

          }
        ); //close GDownloadUrl
  } //close GBrowserIsCompatible
} //close load