Mega-newbie question

I'm looking to use PAM (under RH 7.2)  to enforce a "too many bad login
attempts & you're locked out" policy.  I've done a fair amount of pawing
around & haven't seen anything yet that addresses this (of course, I may
just not be understanding what I was seeing!)  I really appreciate it if
someone be kind enough to point me in the direction of a good reference as
to how to do this?

Many Thanks, Steve Hurd