function InventoryItem_after_insert($data, $memberInfo, &$args) {
$new_qty=sqlvalue("SELECT IFNULL(i.Quantity,0)-{$data['Add']} from InventoryItem i where i.itemtype= {$data['itemtype']}");
sqlvalue("UPDATE Inventoryitem i set i.Quantity = {$new_qty} where i.itemtype ={$data['itemtype']}");
return TRUE;
}