GMarkerOptions options = new GMarkerOptions(topMap, topMap.getCenter()).draggable(true);
final GMarker marker = new GMarker(options);
final Label label = new Label("label", new PropertyModel<GLatLng>(marker, "latLng"));
label.setOutputMarkupId(true);
add(label);
marker.addListener(GEvent.dragend, new GEventHandler()
{
private static final long serialVersionUID = 1L;
@Override
public void onEvent(AjaxRequestTarget target)