extjs中的fileuploadfield出现两个按钮

extjs中的fileuploadfield出现两个按钮，由于没有导入ext/3.0.0/examples/ux/FileUploadField.js样式

/** * @author edwin * @date 2011-1-30 * @desc 上传窗体 */uploadWin = Ext.extend(Ext.Window,{id: 'upLoad',uploadPanel: null,constructor: function(){this.uploadPanel = new Ext.form.FormPanel({fileUpload: true,//允许上传baseCls: 'x-plain',//作用在面板元素上的CSS样式类 （默认为 'x-panel')layout: 'form',labelWidth: 60,items: [{xtype: 'fileuploadfield',//引入插件fieldLabel: '上传照片',allowBlank: false,id: 'photo',buttonText: '选择'}]});//调用父类构造方法uploadWin.superclass.constructor.call(this,{title: '上传照片',modal: true,width: 380,height: 150,plain: true,items:[this.uploadPanel],buttonAlign: 'center',buttons:[{text: '确定'},{text: '取消'}]})}})