function initialize() {
      if (GBrowserIsCompatible()) {
        var map = new GMap2(document.getElementById("map_canvas"));
	// Kaart-Satelliet-Hybride control toevoegen
	map.addControl(new GMapTypeControl());
	// Grote zoom control toevoegen
	map.addControl(new GLargeMapControl());
	// Midden instellen
	map.setCenter(new GLatLng(51.992491, 5.099030), 11);
 
 //Create marker and set up event window
  function createMarker(point,html){
        var marker = new GMarker(point);
        GEvent.addListener(marker, "click", function() {
            marker.openInfoWindowHtml(html);
        });
        return marker;
  }
  
 //create randomnumber and retrieve xml file
    var randomnumber=Math.floor(Math.random()*11111)
    GDownloadUrl("data.xml?random="+randomnumber, 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");
        map.addControl(new GMapTypeControl());
        var marker = createMarker(point,html);
        map.addOverlay(marker);
    } //close for loop

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