using roles provider in mvc2 application

i have function named comments with attributes [Authorize(Roles="Admin,Users")]. I have edit button for comments. On the Edit function we have attribute [Authorize(Roles="Adm开发者_Go百科in")]. When User tries to access i want to throw a custom error page.I am not using forms authentication just roles provider. How can i redirect to custom error page.

Write a custom attribute

eg

public class CustomAuthorizeAttribute : AuthorizeAttribute
    {
        private string[] UnAuthorizedRoles = new string[] { "USER" };

        protected override bool AuthorizeCore(System.Web.HttpContextBase httpContext)
        {
            bool authorized = true;
            foreach (string role in UnAuthorizedRoles)
            {
                if (httpContext.User.IsInRole(role))
                {
                    authorized = false;
                }
            }
            return authorized;
        }


        protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
        {
           // send to custom error page
        }
    }