var map = L.map('map', {
                    minZoom: 1,
                    maxZoom: 4,
                    center: [0, 0],
                    zoom: 0,
                    crs: L.CRS.Simple
                });

                // dimensions of the image
                var w = 3200,
                    h = 1900,
                    url = 'assets/img/isbimg.jpg';
                url1 = 'assets/img/fjmap.png';
                // calculate the edges of the image, in coordinate space
                var southWest = map.unproject([0, h], map.getMaxZoom() - 1);
                var northEast = map.unproject([w, 0], map.getMaxZoom() - 1);
                var bounds = new L.LatLngBounds(southWest, northEast);

                var featureGroup = L.featureGroup().addTo(map);

                var drawControl = new L.Control.Draw({
                    edit: {
                        featureGroup: featureGroup
                    },
                    draw: {
                        polygon: true,
                        polyline: true,
                        rectangle: true,
                        circle: true,
                        marker: true
                    }
                }).addTo(map);


                map.on('draw:created', showPolygonArea);
                map.on('draw:edited', showPolygonAreaEdited);
                // add the image overlay,
                // so that it covers the entire map

                var iii = L.imageOverlay(url1, bounds);
                var jjj = L.imageOverlay(url, bounds);
                var ggg = iii.addTo(map);
                var hhh = jjj.addTo(map);

                jjj.addTo(map);
                $('#layerControl').on('click', function layerControl() {
                    ggg.bringToFront();
                    return this;
                });

                $('#layerControl2').on('click', function layerControl2() {
                    hhh.bringToFront();
                    return this;
                });