一个EXT问题

var projectBaseInfoPanel = new Ext.Panel({
title:'基本信息',
id:'projectBaseInfoPanel',
layout:'border',
autoScroll:true,
bodyStyle:"overflow-x:hidden",//overflow-y:scroll",//;overflow-x:hidden
items:[projectForm],
tbar : projectTopBar//,landEditBtn]
});
总是报这个错，
uncaught exception: No center region defined in BorderLayout projectBaseInfoPanel
有经验的大侠帮我看看布局哪里出问题了

border布局有个region属性 缺少这个属性 给你个例子
JScript code

Ext.onReady(function(){  
  var border = new Ext.Panel({  
  renderTo: Ext.getBody(),
  //title: 'Border Layout',  
  width:1000,
  height:300,
  layout:'border',  
  items: [{  
  title: 'South Panel',  
  region: 'south',  
  height: 100,  
  minSize: 75,  
  maxSize: 250,  
  margins: '0 5 5 5'  
  },{  
  title: 'West Panel',  
  region:'west',  
  margins: '5 0 0 5',  
  cmargins: '5 5 0 5',  
  width: 200,  
  minSize: 100,  
  maxSize: 300  
  },{  
  title: 'Main Content',  
  region:'center',  
  margins: '5 5 0 0'  
  }]  

});  
});