extjs报错 c.header is undefined 求大侠帮看下

[小罗公子]

  Ext.onReady(function () {
            Ext.QuickTips.init();
            var iframePanel = new Ext.Panel({
                style: 'padding:0px 0px 0px 5px;',
                viewConfig: {
                    loadingText: "正在加载..."
                },
                border: false,
                html: ' <iframe id="leftIframe" width="100%" Height="555px" src="ShowReport.aspx" scrolling="no" frameborder="0" border="0" marginheight="0" allowtransparency="yes"> </iframe>'
            });
            var root = new Ext.tree.AsyncTreeNode
            ({
                id: "-100", //根节点id
                text: "xx"
            });
            //定义树节点

            var panelmenu = new Ext.Panel({
            id:"menu",
                width: 200,
                nimSize: 200,
                collapsible: true,
                collapseMode: 'mini',                
                layout: 'accordion'
            });
            root.appendChild(new Ext.tree.TreeNode({
            id:"xxx",
            test:"xxx"
            }))
            Ext.getCmp( "menu").add(new Ext.Panel({
                title: "test",
                id: "test",
                items: [new Ext.tree.TreePanel({
                    render:"show",                                                         
                    autoScroll: true,
                    containerScroll: true,
                    expanded: false,
                    root: root,
                    animate: true, 
                    enableDD: false, 
                    border: false, 
                    rootVisible: true                    
            }));
            var tabePanel = new Ext.TabPanel({
                //                region: 'center',
                id: 'MainTabPanel',
                activeTab: 0,
                split: true,
                items: [{
                    title: 'Home',
                    items: iframePanel
                }]
            });
            //整体布局

            var viewport = new Ext.Viewport({
                layout: 'border',
                renderTo: Ext.getBody(),
                items: [
                {
                    region: 'north',
                    frame: false,
                    xtype: 'panel',
                    height: 50,
                    html: ' <div id="Header"><div id="Banner"></div></div>'
                },

            {
                region: 'west',
                xtype: 'panel',
                split: true,
                width: 200,
                nimSize: 200,
                title: "菜单",
                collapsible: true,
                collapseMode: 'mini',
                //                items:extPanel
                //              margins:'0 0 0 5',                   
                layout: 'accordion',
                layoutConfig:
                 {
                     animate: true
                 },
                items: panelmenu
               }]
            },
            {
                region: 'center',
                xtype: 'panel',
                activeTab: 0,
                split: true,
                border: false,
                items: tabePanel        

            },
            {
                region: 'south',
                xtype: 'panel',
                split: true,
                frame: true,
                htmlAlign: 'center',
                html: '<div style="text-align:center">test</div>'
            }
            ]
            });
        })