item.stock_id,
item.description,
line.unit_price * trans.rate AS unit_price,
- SUM(line.quantity) as quantity
+ SUM(IF(line.debtor_trans_type = ".ST_CUSTCREDIT.", -line.quantity, line.quantity)) AS quantity
FROM ".TB_PREF."stock_master item,
".TB_PREF."stock_category category,
".TB_PREF."debtor_trans trans,