Password expiration script

I'm looking for a script that would require a user to change their password every 30 days. Does anyone use a script that has functionality similar to what I'm looking for? Thanks, Dave HTC Disclaimer: The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you.