You run a tracker this should be bread and butter creating table entrys anyhoo :
PHP Code:
ALTER TABLE users ADD `invitedby` int(10) unsigned NOT NULL default '0';
The op must have neglected to check that there was 2 user table entries required for this mod when he posted it. I'll assit with missing sql i was on Tbdev long enough to know every single modification used, there is no way im fixing the code, i already done that for Tbdev.