var drawnItems = new L.FeatureGroup();
    map.addLayer(drawnItems);

    map.on('draw:created', function (e) {
        var type = e.layerType,
        layer = e.layer;
        drawnItems.addLayer(layer);
    });

    polygon_options = {
        allowIntersection: false,
                drawError: {
                    color: '#b00b00',
                    timeout: 1000
        },
                showArea: true,
                metric: false,
                repeatMode: false,
        shapeOptions: {
            stroke: true,
            color: '#6e83f0',
            weight: 4,
            opacity: 0.5,
            fill: true,
            fillColor: null,
            fillOpacity: 0.2,
            clickable: true
        }
    }

    function drawPolygon(){
            var polygonDrawer = new L.Draw.Polygon(map, polygon_options);
        polygonDrawer.enable();
    }