Member redirection to login page and upgrade member

Hi,
I am using role based authentication in my web application. Now i am using roles say "member" and "senoirMember"

Well when someone tries to access unauthorized zone they r perfectly redirected to the login page. The problem for me now is that when a member tries to access the senoirMember features i want him to be redirected to upgrade membership form and not to the login page. Can anyone help me on this.

Thanks,
Imran.

Maybe check if the user is in the Role of "member" on the login page, and if so, redirect them to the "upgrade membership" page?