Passing message to login failure page from a customer realm

[Surya Mishra]

Hi,

I want to show a error page when the login fails. And I want to show a
custom message whenever there is some system error like if the user database
is down or there is a network failure. How can I pass on the message from my
customer realm to the error page? The realm doesn't have access to
HttpSession or HttpServletRequest. or does it?

Thanks
-Surya