If you add this:
PHP Code:
$the_pm_id = $DB_site->insert_id();
right below this:
PHP Code:
$DB_site->query("INSERT INTO privatemessage (privatemessageid,userid,touserid,fromuserid,title,message,dateline,showsignature,iconid,messageread,folderid,receipt) VALUES (NULL,$touserinfo[userid],$touserinfo[userid],$bbuserinfo[userid],'".addslashes(htmlspecialchars($title))."','".addslashes($message)."',".time().",'$signature','$iconid',0,0,$receipt)");
and put this as a link to the private message, you can save making a new query.
PHP Code:
$bburl/private.php?action=show&privatemessageid=$the_pm_id