How can I customize this error message?

Hello,

I extended System.Web.Http.AuthorizeAttribute, and provided implementation of IsAuthorized method.

When the authorization failed, the error message I got is {"message":"Authorization has been denied for this request."} provided by ASP.NET Web API.

Is there any way I can customize this error message?

For example, what if I want to response out like {"message":"...", "deatil" : "blahblah"} when authorization failed?

Thanks,