Syntax:
OLD_PASSWORD(str)

OLD_PASSWORD() was added when the implementation of PASSWORD() was
changed in MySQL 4.1 to improve security. OLD_PASSWORD() returns the
value of the pre-4.1 implementation of PASSWORD() as a binary string,
and is intended to permit you to reset passwords for any pre-4.1
clients that need to connect to your version 5.1 MySQL server without
locking them out. See
http://dev.mysql.com/doc/refman/5.1/en/password-hashing.html.

URL: http://dev.mysql.com/doc/refman/5.1/en/encryption-functions.html

