// init function will be executed when dom is ready
function init() {
  if (GBrowserIsCompatible()) {
    // Create a new google map
    var map = new GMap2(document.getElementById('map_sample2'));
     
    // Center on the world
    map.setCenter(new GLatLng(47, 1), 4);
     
    // Add controls
    map.addControl(new GSmallMapControl());
    
     // Attach maptimize service
    var maptimizeMap = new Maptimize.Map(map, {
      onMarkerClicked: function(marker) {
        // marker: is an instance of Maptimize.Marker
        marker.getGMarker().openInfoWindowHtml('ID = ' + marker.getId());
      },
      onZoomMaxClusterClicked: function(cluster, ids) {
        // cluster: is an instance of Maptimize.Cluster
        cluster.getGMarker().openInfoWindowHtml('IDS = ' + ids);
      }
    });
  }
}

// Code based on Prototype. Of course you can use any JavaScript framework
// like jQuery for example : $(document).ready(init);
//
// Or use window onload event : window.onload = init;
document.observe('dom:loaded', init);