extjs window嵌套FormPanel ，显示不了FormPanel，求问原因，谢谢大神的指导

[琉璃小小楠]

//员工工作经历添加
        this.form_ygjob = new Ext.form.FormPanel({
            id: 'form_ygjob'
            , width: 550
            , frame: true
            , labelSeparator: ':'
            , labelWidth: 90
            , labelAlign: 'right'
            , layout: 'form'
            , style: 'text-align:left;'
            , items: [
                {
                    xtype: 'fieldset'
                    , title: '工作经历'
                    , layout: 'column'
                    , items: [
                        {
                            columnWidth: .25
                            , border: false
                            , scope: this
                            , layout: 'form'
                            , items: [
                                {
                                    xtype: 'textfield'
                                    , id: 'textfirm'
                                    , name: 'txtfirm'
                                    , fieldLabel: '公司名称'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'datefield'
                                    , id: 'textworktime'
                                    , name: 'txtworktime'
                                    , fieldLabel: '工作开始时间'
                                    , format: 'Y-m-d'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'textfield'
                                    , id: 'textvoucher'
                                    , name: 'txtvoucher'
                                    , fieldLabel: '证明人'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'textfield'
                                    , id: 'textleavecause'
                                    , name: 'txtleavecause'
                                    , fieldLabel: '离职原因'
                                    , anchor: '93%'
                                }
                            ]
                        }
                        , {
                            columnWidth: .25
                            , border: false
                            , scope: this
                            , layout: 'form'
                            , items: [
                                {
                                    xtype: 'textfield'
                                    , id: 'textduty'
                                    , name: 'txtduty'
                                    , fieldLabel: '职务'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'datefield'
                                    , id: 'textoverworktime'
                                    , name: 'txtoverworktime'
                                    , fieldLabel: '工作结束时间'
                                    , format: 'Y-m-d'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'textfield'
                                    , id: 'textvoucherphone'
                                    , name: 'txtvoucherphone'
                                    , fieldLabel: '证明人电话'
                                    , anchor: '93%'
                                }
                                , {
                                    xtype: 'textfield'
                                    , id: 'textworkremark'
                                    , name: 'txtworkremark'
                                    , fieldLabel: '工作备注'
                                    , anchor: '93%'
                                }
                            ]
                        }
                    ]
                }
            ]
        });
        this.win_ygjob = new Ext.Window({
            id: 'win_ygjob'
            , layout: 'fit'
            , width: 500
            , autoHeight: true
            , bodyStyle: 'padding:5'
            , animCollapse: true
            , closeAction: 'close'
            , shadow: false
            , modal: true
            , items: [this.form_ygjob]
            , buttonAlign: 'center'
            , buttons: [
                new Ext.Button({
                    text: ' 保 存 '
                    , id: 'btnsave_ygjob'
                    , width: 50
                    , scope: this
                    , handler: this.save_ygjob
                })
                , new Ext.Button({
                    text: ' 取 消 '
                    , id: 'btnexit_ygjob'
                    , width: 50
                    , scope: this
                    , handler: function () {
                        this.win_ygjob.hide();
                    }
                })
            ]
        });
        //员工工作经历
        this.cm_ygjob = new Ext.grid.ColumnModel([
            { header: "编号", dataIndex: "id", align: 'center', width: 50, hidden: true }
            , { header: "公司名称", dataIndex: "jobUnit", align: 'center' }
            , { header: "职务", dataIndex: "duties", align: 'center' }
            , { header: "证明人", dataIndex: "prover", align: 'center' }
            , { header: "证明人电话", dataIndex: "proverMobile", align: 'center' }
            , { header: "离职原因", dataIndex: "leaveReson", align: 'center' }
            , { header: "工作开始时间", dataIndex: "jobStartDate", align: 'center' }
            , { header: "工作结束时间", dataIndex: "jobEndDate", align: 'center' }
            , { header: "工作备注", dataIndex: "description", align: 'center' }
        ]);
        this.store_ygjob = new Ext.data.Store({
            proxy: new Ext.data.HttpProxy({ url: '/Employee/ReadGetOutMaterDet' }),
            reader: new Ext.data.JsonReader({
                root: 'empList'
            }, [
                { name: 'id' }
                , { name: 'jobUnit' }
                , { name: 'duties' }
                , { name: 'prover' }
                , { name: 'proverMobile' }
                , { name: 'leaveReson' }
                , { name: 'jobStartDate' }
                , { name: 'jobEndDate' }
                , { name: 'description' }
            ])
        });
        this.grid_ygjob = new Ext.grid.GridPanel({
            id: 'grid_ygjob'
            , cm: this.cm_ygjob
            , store: this.store_ygjob
            , autoDestroy: true
            , frame: true
            , tbar: [
                {
                    pressed: true
                    , text: "添加工作经历"
                    , scope: this
                    , width: 80
                    , handler: function () {
                        this.win_ygjob.show();
                        this.win_ygjob.setTitle("添加工作经历");
                        this.form_ygjob.getForm().reset();
                        Ext.getCmp('btnsave_ygjob').show();
                        Ext.getCmp('btnexit_ygjob').show();
                    }
                }
            ]
        });