un-encrypting passwords

Hi, I've got a PHP/MySQL site that uses a simple user table to check for a valid username/password match when logging someone in. I encrypted the passwords using mysql's PASSWORD() function. I now realize that was probably not the best choice, because I don't think it's possible to un-encrypt them. I want to add a feature that allows users to request to have their password emailed to them. Can anyone recommend a better method for encypting passwords and how to unencrypt? (is there a function in PHP for this? Or a different MySQL function?) Thanks, Sam -- Sam Folk-Williams Service Team Leader/Webmaster Rise, Inc -- Creative Partnerships South (952) 884 8330 (V); (952) 884 8371 (F) www.rise.org