Forum Moderators: coopster
You can use the $_SERVER['REMOTE_ADDR'] superglobal to check the visitors IP address. Find out what IP addresses your office uses and then deny or redirect users that don't have that address.
If you want to do a login based system, here's a good thread [webmasterworld.com] from the forum library [webmasterworld.com] that discusses how to do it.
If you start to implement either and run into trouble, post back here with what you've got so far and we'd be happy to help. :)