extjs portal 怎么动态增加小模块呢？


var portpage1 = new Ext.Panel({
    collapsible: true,
    title: '第一页',
    layout: {
        type: 'border',
        padding: '0 5 5 5'
    },
    items: [{
        xtype: 'container',
        region: 'center',
        layout: 'border',
        height: 500,
        items: [{
            id: 'app-portal1',
            xtype: 'portalpanel',
            region: 'center',
            items: [{
                id: 'col-1',
                items: [{
                    id: 'app1id',
                    title: '应用1',
                    tools: this.getTools(),
                    items: [{
                        xtype: 'panel',
                        region: 'north',
                        items: [{
                            region: 'north',
                            height: 50,
                            border: false,
                            items: [{
                                xtype: 'button',
                                text: '管理1',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理2',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理3',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }]
                        }, {
                            id: 'app1idcontent',
                            region: 'center',
                            height: 150,
                            html: content1()
                        }]
                    }],
                    height: 200,
                    listeners: {
                        'close': Ext.bind(onPortletClose, this)
                    }
                }, {
                    id: 'app2id',
                    title: '应用2',
                    tools: this.getTools(),
                    items: [{
                        xtype: 'panel',
                        region: 'north',
                        items: [{
                            region: 'north',
                            height: 50,
                            border: false,
                            items: [{
                                xtype: 'button',
                                text: '管理1',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理2',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理3',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }]
                        }, {
                            id: 'app2idcontent',
                            region: 'center',
                            height: 150,
                            html: content()
                        }]
                    }],
                    height: 200,
                    listeners: {
                        'close': Ext.bind(onPortletClose, this)
                    }
                }]
            }, {
                id: 'col-2',
                items: [{
                    id: 'app3id',
                    title: '应用3',
                    tools: this.getTools(),
                    items: [{
                        xtype: 'panel',
                        region: 'north',
                        items: [{
                            region: 'north',
                            height: 50,
                            border: false,
                            items: [{
                                xtype: 'button',
                                text: '管理1',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理2',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理3',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }]
                        }, {
                            id: 'app3idcontent',
                            region: 'center',
                            height: 270,
                            autoScroll: true, //允许伸缩
                            html: contenttable()
                        }]
                    }],
                    height: 350,
                    listeners: {
                        'close': Ext.bind(onPortletClose, this)
                    }
                }]
            }, {
                id: 'col-3',
                items: [{
                    id: 'app4id',
                    title: '应用4',
                    tools: this.getTools(),
                    items: [{
                        xtype: 'panel',
                        region: 'north',
                        border: false,
                        items: [{
                            region: 'north',
                            height: 50,
                            items: [{
                                xtype: 'button',
                                text: '管理1',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理2',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }, {
                                xtype: 'button',
                                text: '管理3',
                                scale: 'small',
                                iconCls: 'add',
                                iconAlign: 'top'
                            }]
                        }, {
                            id: 'app4idcontent',
                            region: 'center',
                            height: 120,
                            autoScroll: true, //允许伸缩
                            html: content1()
                        }]
                    }],
                    height: 200,
                    listeners: {
                        'close': Ext.bind(onPortletClose, this)
                    }
                }]
            }]
        }]
    }]
});这样能初始化几个小窗体，如何动态的添加小模块呢