function startUp() {
	var map = new GMap2( document.getElementById("mymap") );
	var point = new GLatLng(39.904041101073, 141.6246485710144);
	map.setCenter( point, 5 );

	map.addControl(new GSmallMapControl());
	map.addControl(new GScaleControl());
	map.addControl(new GOverviewMapControl());

	var mk = new GMarker( point );
	map.addOverlay(mk);
}

onload   = startUp;
onunload = GUnload;