本代码所展示出来的的是如下图所示：

Ext.onReady(function(){Ext.QuickTips.init();     var tree=new   Ext.tree.TreePanel({    //   el:"tree"   });    var root=new Ext.tree.TreeNode({text:'项目信息'});    var node1=new Ext.tree.TreeNode({        id:'node1',        text:"项目资料"    });    var node2=new Ext.tree.TreeNode({        id:'node2',        text:'标段信息'    });    var node3=new Ext.tree.TreeNode({        id:'node3',        text:"合同清单"    });    var node4=new Ext.tree.TreeNode({        id:'node4',        text:"形象清单"          });    root.appendChild(node1);    root.appendChild(node2);    root.appendChild(node3);    root.appendChild(node4);    tree.setRootNode(root);    tree.on("click",function(node){               /* var text=node.text;        var mainPanel=Ext.getCmp("main"); //中间主Panel        var url="";        if(text=="项目信息") url="1.jsp";        if(text=="项目资料") url="1.jsp";        if(text=="标段信息") url="2.jsp";        if(text=="合同清单") url="3.jsp";        if(text=="形象清单") url="4.jsp";             mainPanel.load({            url:url,            nocache:true,            text:"正在加载中......",            timeout:30,            scripts:true         });*/            var n;            n = tabPanel.getComponent(node.id);            if(n) {                tabPanel.setActiveTab(n);                return;            }            n = tabPanel.add( {                id : node.id,                title : node.text,                html : '',                closable : 'true'            });            tabPanel.setActiveTab(n);                    });     var tabPanel = new Ext.TabPanel({            region:"center",               plit:true,               border:true,               id:"main",            enableTabScroll : true,            deferredRender : false,            activeTab : 0,            items : [ {                title : 'index',                autoLoad : 'list.jsp'                }]            });        var accordion = new Ext.Panel({        title:'系统菜单',        region:"west",           collapsible:true,           width:200,           layout:"accordion",           layoutConfig:{               titleCollapse:true,               animate:true,               activeOnTop:false                },    items:[{               title:"第一栏",               items:[tree]           },{               title:"第二栏"           },{               title:"第三栏"           }]        });       var viewport=new Ext.Viewport({           enableTabScroll:true,           layout:"border",           items:[               accordion,              tabPanel       ]   });});