var map;
map = new GMap2(document.getElementById("route_map"));
map.setCenter(new GLatLng(35.228233,136.796951), 13);
map.addControl(new GLargeMapControl());
map.addControl(new GMapTypeControl());
map.addControl(new GOverviewMapControl());
map.enableScrollWheelZoom(); 
var url = 'http://maps.google.co.jp/maps/ms?ie=UTF8&hl=ja&oe=UTF8&msa=0&msid=112789537821016221840.00047d7b315ad7df49187&output=kml';

var geoxml = new GGeoXml(url);
map.addOverlay(geoxml);