ExtAspNet控件提示未将对象引用设置到对象的实例

生命有痕

页面中就放一个按钮运行页面就提示 未将对象引用设置到对象的实例。 怎么解决


webconfig文件
<configSections>
  <section name="ExtAspNet"  type="ExtAspNet.ConfigSection,ExtAspNet"/>
</configSections>
<appSettings/>
<connectionStrings/>
<ExtAspNet Language="en" AjaxTimeout="60" />
<system.web>
  <pages>
   <controls>
    <add assembly="ExtAspNet" namespace="ExtAspNet" tagPrefix="ext"/>
   </controls>
  </pages>
  <httpModules>
   <add name="ExtAspNetScriptModule" type="ExtAspNet.ScriptModule, ExtAspNet"/>
  </httpModules>
望高手指教，新手学习！