JS回调函数callback

choose_goods(url, obj,function(res){ 

　　if(res.btn==3&&res.status==1){ 
　　　　console.log(res); 　
　　} 
});

function choose_goods(url, obj,callback) {
        var o = $(obj);
        var garr = new Array();
        garr['status'] = 0;
        layer.open({
            type: 2,
            title: "选择商品",
            shadeClose: true,
            shade: 0.3,
              maxmin: true, //开启最大化最小化按钮
              area: ['900px', '580px'],
              fixed: false, //不固定
              btn: ['新增商品', '选中', '选中并关闭', '取消'],
              //btn: ['btn1','btn2','btn3', 'btn4'],
              content: url,
              btn1: function (index, layero) {garr['btn'] = 1;
                garr['status'] = 1;
                callback(garr);
                return false;            
            },
            btn2: function (index, layero) {
                garr['btn'] = 2;
                //按钮【按钮二】的回调
                garr['status'] = 1;
                callback(garr);
                return false;
            },
            btn3: function (index, layero) {
                garr['btn'] = 3;
                garr['status'] = 0;
               //获取商品信息
                $.get("/admin/basic/one_goods.html", { id: goodid }, function (data, state) {
                    if (data.status == 1) {
                        garr['status'] = 1;
                        garr['data'] = data;
                        layer.close(index);
                        callback(garr);
                    } 
                })
                return false;
            },
            btn4: function (index, layero) {
                layer.close(index);
                return false;
            },
        });
    }