var gmap = null;
    var mapExtension;
	var gOverlays = null;
	var centerat = new GLatLng(41.30875272308545, -72.92854428291321);
	
    function initialize() {
	//Load Google Maps
	gmap = new GMap2(document.getElementById("map"));
	gmap.addControl(new GLargeMapControl());
	gmap.addControl(new GMapTypeControl());
	gmap.setCenter(centerat, 18);
	gmap.enableScrollWheelZoom();
	  
	//Set Map Type
	//gmap.setMapType(G_SATELLITE_MAP);         
	gmap.setMapType(G_HYBRID_MAP);
	//gmap.setMapType(G_PHYSICAL_MAP);
	//gmap.setMapType(gMapType0);
	
	//create mapextension class to be used to add/remove results from the map.
	mapExtension = new esri.arcgis.gmaps.MapExtension(gmap);
	
	//create tileparam to specify opacity, minResolution, maxResolution when adding to the map.
	var tileparam = {opacity: 1.0, minResolution:15, maxResolution: 19};
	  
	//create custom tile layer array

	var tiledMap = new Array();
	tiledMap[0] = new esri.arcgis.gmaps.TiledMapServiceLayer("http://mercator.library.yale.edu:8399/arcgis/rest/services/DNH/1886_Sanborn_New_Haven/MapServer", tileparam,
	function(gTO) { 
		addTiledMap(gTO, "1886") 
	});

	tiledMap[1] = new esri.arcgis.gmaps.TiledMapServiceLayer("http://mercator.library.yale.edu:8399/arcgis/rest/services/DNH/1901_Sanborn_New_Haven/MapServer", tileparam, 
	function(gTO) { 
		addTiledMap(gTO, "1901") 
	});

	tiledMap[2] = new esri.arcgis.gmaps.TiledMapServiceLayer("http://mercator.library.yale.edu:8399/arcgis/rest/services/DNH/New_Haven_Atlas_1911/MapServer", tileparam, 
	function(gTO) { 
		addTiledMap(gTO, "1911") 
	});

    tiledMap[3] = new esri.arcgis.gmaps.TiledMapServiceLayer("http://mercator.library.yale.edu:8399/arcgis/rest/services/DNH/1924_Sanborn_New_Haven/MapServer", tileparam, 
	function(gTO) { 
		addTiledMap(gTO, "1924") 
	}); 

	tiledMap[4] = new esri.arcgis.gmaps.TiledMapServiceLayer("http://mercator.library.yale.edu:8399/arcgis/rest/services/DNH/1973_Sanborn_New_Haven/MapServer", tileparam, 
	function(gTO) { 
		addTiledMap(gTO, "1973") 
	});
}
 function addTiledMap(gTileLayer, label) {

	//Add tile layer as a new GMapType  
	var tilelayer0 = [G_SATELLITE_MAP.getTileLayers()[0],gTileLayer];
	var gMapType0 = new GMapType(tilelayer0, new GMercatorProjection(20), label, {errorMessage:"No data available"});
	gmap.addMapType(gMapType0);
	gmap.removeMapType(G_NORMAL_MAP);
	gmap.removeMapType(G_HYBRID_MAP);
	gmap.removeMapType(G_SATELLITE_MAP);
	gmap.addMapType(G_HYBRID_MAP);
	gmap.addMapType(G_NORMAL_MAP);
	//gmap.addMapType(G_PHYSICAL_MAP);
}

window.onload = initialize;
window.onunload = GUnload;