      ]
            ),

            '默认地图': L.tileLayer('http://map.geoq.cn/ArcGIS/rest/services/ChinaOnlineCommunity/MapServer/tile/{z}/{y}/{x}').addTo(map)
        };

        // 默认地图图层为MapBox
        L.tileLayer('https://a.tiles.mapbox.com/v3/foursquare.map-0y1jh28j/{z}/{x}/{y}.png', 
        {
            attribution: 'Map &copy; Pacific Rim Coordination Center (PRCC).  Certain data &copy; <a href="http://openstreetmap.org">OpenStreetMap</a> contributors, <a href="http://creativeco