Oracle Forms

Dear Friends
I have this problem, I want my form to save each record when the user enter the Quantity on the field qty, so I have written this code on KEY-NEXT-ITEM TRIGGER, it works fine if the user press enter key on qty but, if the user move from qty by using the mouse, this code is not executed, how can I handle this code if the user is not use the enter key and move to the next record by the mouse .
I am waiting for your valuable answer .

Best Regards
Ali
This the code that I am using in KEY-NEXT-ITEM TRIGGER
DECLARE
LOC_QTY_ON_HAND NUMBER(8);
LOC_OLD_QTY NUMBER(8);
LOC_QTY_REC NUMBER(8);

BEGIN
IF :SYSTEM.RECORD_STATUS ='NEW' OR :SYSTEM.RECORD_STATUS='INSERT' AND NVL(:REC_DETAILS.QTY,0) !=0 THEN
SELECT (NVL(QTY_ON_HAND,0) - (:REC_DETAILS.QTY)),QTY_ON_HAND
INTO LOC_QTY_ON_HAND,LOC_OLD_QTY
FROM MAINTENANCE_ITEM
WHERE ITEM_CODE = :D_ITEM_CODE;
IF LOC_QTY_ON_HAND >=0 THEN

UPDATE MAINTENANCE_ITEM
SET QTY_ON_HAND = LOC_QTY_ON_HAND
WHERE ITEM_CODE = :D_ITEM_CODE;
COMMIT_FORM;
MESSAGE('Data have been saved');
ELSIF LOC_QTY_ON_HAND < 0 THEN
MESSAGE('Balance Quantity can not be less than zero !!! ');

END IF;
RAISE FORM_TRIGGER_FAILURE;
END IF;

END;
NEXT_RECORD;