PassportIdentity identity = (this.Context.User.Identity as PassportIdentity);    
        // Determine whether the user is already signed in with a valid
        // and current ticket. Passing -1 for the parameter values 
        // indicates the default values will be used.
        if (identity.GetIsAuthenticated(-1, -1, -1))
        {
            this.Response.Write("Welcome to the site.<br /><br />");
            // Print the Passport sign in button on the screen.
            this.Response.Write(identity.LogoTag2());
            // Make sure the user has core profile information before
            // trying to access it.
            if (identity.HasProfile("core"))
            {
                this.Response.Write("<b>You have been authenticated as " + 
                    "Passport identity:" + identity.Name + "</b></p>");
            }
        }

        // Determine whether the user has a ticket.
        else if (identity.HasTicket)
        {
            // If the user has a ticket but wasn't authenticated, that 
            // means the ticket is stale, so the login needs to be refreshed.
            // Passing true as the fForceLogin parameter value indicates that 
            // silent refresh will be accepted.
            identity.LoginUser(null, -1, true, null, -1, null, -1, true, null);
        }