mysql_query("DELETE FROM user WHERE (lastvisit<'.(time() - (60 * 60 * 24 * 487)).') AND (usergroupid IN (2, 3, 10, 11)",$db);
mysql_query("DELETE FROM user WHERE (lastvisit<" . (time() - (60 * 60 * 24 * 487)) . ") AND (usergroupid IN (2, 3, 10, 11)",$db);