How can I remove or empty all Private messages

[TriGGeR]

I have a site and I have installed the read private message hack. Here is my question, I would like to empty ALL private message boxes on the site once a month. How can I do this? I can read them but can't delete them. This is very important to me as I like a clean ship. I asked member to do it but there are some that just can't follow rules.

[Steve Machol]

To delete all PMs, run these 4 queries:

UPDATE `user` SET `pmtotal` = '0',`pmunread` = '0';
TRUNCATE TABLE `pm`;
TRUNCATE TABLE `pmtext`;
TRUNCATE TABLE `pmreceipt`;

Of course, backup your database first.