百度地图折线覆盖物添加起点和终点？？

   //添加时
  map1.addEventListener("click", function (e) {
            if (doDraw == 0) { //判断是否绘制曲线完毕
                var point = new BMap.Point(e.point.lng, e.point.lat);
                points.push(point); //存储曲线上每个点的经纬度
                var polyline = new BMap.Polyline(points, { strokeColor: "red", strokeWeight: 3, strokeOpacity: 0.5 });
                map1.addOverlay(polyline);
                v_ReservoirArea += e.point.lng + "," + e.point.lat + ";";
                $("#txt_Coordinate").textbox('setValue', v_ReservoirArea);//获取经纬度到文本框，已空格隔开

              
                var marker = new BMap.Marker(points[0]);
                marker.setLabel(new BMap.Label("起点"));
                map1.addOverlay(marker);
               
            }
        });

        map1.addEventListener("dblclick", function (e) { //当鼠标双击时：结束绘制，
            var paths = points.length;
            var marker1 = new BMap.Marker(points[paths - 1]);
            marker1.setLabel(new BMap.Label("终点"));
            map1.addOverlay(marker1);
            alert("绘制完成！");
            doDraw = 1;
            
        });



//修改时
 var sPoint = opticalCoordinate.split(";");
                if (sPoint != null && sPoint != "") {

                    var se = [];
                    for (var j = 0; j < sPoint.length; j++) {
                        var pointItem = sPoint[j].split(",");

                        if (pointItem != null && pointItem != "") {
                            var Lon = pointItem[0];
                            var Lat = pointItem[1];
                            se.push(new BMap.Point(Lon, Lat));
                            
                        }
                    }
                 

                    //map1 = new BMap.Map("OpticalMap");    // 创建Map实例
                    //map1.centerAndZoom(new BMap.Point(se[0].lng,se[0].lat), 11);  // 初始化地图,设置中心点坐标和地图级别
                    //map1.addControl(new BMap.NavigationControl());//左上角，添加默认缩放平移控件
                    //map1.addControl(new BMap.MapTypeControl());   //添加地图类型控件
                    //map1.setCurrentCity(v_CityName);          // 设置地图显示的城市 此项是必须设置的
                    //map1.enableScrollWheelZoom(true);     //开启鼠标滚轮缩放
                  
                    var polyline = new BMap.Polyline(se, { strokeColor: "red", strokeWeight: 3, strokeOpacity: 0.5 });
                    map1.addOverlay(polyline);

                    var marker = new BMap.Marker(se[0]);
                    marker.setLabel(new BMap.Label("起点"));
                    map1.addOverlay(marker);

                    var paths = se.length;
                    var marker1 = new BMap.Marker(se[paths - 1]);
                    marker1.setLabel(new BMap.Label("终点"));
                    map1.addOverlay(marker1);