layui父窗体获取弹出窗体元素

       layer.open({
                            type: 2,
                            title: '新增任务',
                            skin: 'layui-layer-rim',
                            area: ["1000px", "600px"],
                            content: "TaskOrder_Edit",
                            btn: ["确认", "关闭"],
                            yes: function (index, layero) {
                                var taskOrderData = {};
                                var body = layer.getChildFrame('body', index);
                                var no = body.find('#no').val();
                                var stepName = body.find('#stepName').val();
                            },
                            btn2: function () { }
                        });