How can I check the notification-based cache invalidation with my SQL server 2005 really w

I have used the notification-based cache invalidation with my web application, but how can I check it really works? I mena if the backend data didn't change , the data will come from cache not from the database?

<asp:SqlDataSource ID="SqlDataSource_WebInfo" runat="server" ConnectionString="<%$ ConnectionStrings:LocalSqlServer %>"
SelectCommand="SELECT simplified, traditional FROM temp" ProviderName="System.Data.SqlClient" EnableCaching="True" SqlCacheDependency="CommandNotification">

</asp:SqlDataSource>

Thanks a lot!

I believe, but not sure now, there is a callback function you can register and use, then it happens the function will be call with the ID you selected