pageBaseType issues in web.config file

[Suresh.Eddala]

Hi,
I have added base class to all my pages in App_Code folder, and then
added following line of code in web.config file.

<system.web>
<pages theme="Blue" pageBaseType="ThemedPage" />
</system.web>

ThemedPage.cs code

public class ThemedPage:Page
{
public ThemedPage()
{
//
// TODO: Add constructor logic here
//
}

protected override void OnPreInit(EventArgs e)
{
base.OnPreInit(e);
this.Theme = "Blue";
}
}

When I build the site, I am getting following error message.

Error 1 Make sure that the class defined in this code file matches the
'inherits' attribute, and that it extends the correct base class (e.g.
Page or UserControl). D:\Dot Net\Practice\Default.aspx.cs 12 14 D:\...\
I am trying on net, not much help. Can anyone please tell me where I am
doing wrong..

Thanks
Suresh