function initialize() {
      if (GBrowserIsCompatible()) {
        var map = new GMap2(document.getElementById("map_canvas"));
        map.setCenter(new GLatLng(35.617312,139.775627), 16);
        map.addControl(new GSmallMapControl());
        map.addControl(new GMapTypeControl());


  


       // Add 10 markers to the map at random locations
var bounds = map.getBounds();
var southWest = bounds.getSouthWest();
var northEast = bounds.getNorthEast();
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
for (var i = 0; i < 10; i++) {
  var point = new GLatLng(35.617312,139.775627);
  map.addOverlay(new GMarker(point));
}

      
    }
 }