decrypting passwords

User enters a new password through a form. Then it is put in the table by the following. ($userid is the username) $query = mysql_query("update users set password = encrypt('$password','$userid') where userid = '$userid'") or die("Couldn't execute query."); I need to know how to decrypt the password so that I can have it emailed to the user should they forget it. Any help would be appreciated Thanks Steph