<system.diagnostics>
     <trace>
       <listeners>
         <add name="WebPageTraceListener"
             type="System.Web.WebPageTraceListener,
             System.Web,
             Version=4.0.0.0,
             Culture=neutral,
             PublicKeyToken=b03f5f7f11d50a3a" />
       </listeners>
     </trace>
   </system.diagnostics>