Issue file (newbie)

[Langa Kentane]

I am using Redhat 5.1 and what I want to do is change what is displayed
before the login prompt for user that telnet and for me when I am sitting on
the console.

The problem now is that when I change the contents of the issue file and
then logout, it displays what I want.  As soon as I reboot the old message
comes back on there..

What can I do to remedy this... it's very irritating!