how to configure /etc/nologin

Fri Apr 13 15:46:18 UTC 2007

Hello all,

i am trying to config pam_nologin by creating an empty file in /etc/nologin but when i edit /etc/pam.d/login and /etc/pam.d/system-auth ... nothing happen ?!!!

i cannot login with the root user even local users can not!!!
how can i config my linux RedHat ES 4..to let only the root login and other local users not?!!
what shall i do... or what i need to edit in /etc/pam.d/login and /etc/pam.d/system-auth

Regards,