Using group policy to get passwords to be reset in 14 days

I need to have my users reset their passwords in 14 days. I would like for

the users to receive a notice when they login that their password will expire

in 14 days. I have tried using group policy to try and make this happen.

However I have not been successful in getting the GPO to enforce. This is in

a Windows Server 2003 standard domain.

Can you send me a knowledge base article on how to make this happen?

Thanks

Jim