Oracle Forms

Hello everyboady,i have the following code on when-new block instance ,i want to enter a datein a non -database block ,if such a date of table1 has record it inserts on the table2 and excute query on the detail block..
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FOR I IN MATERIALS
LOOP
INSERT INTO PLN_DAILY_PRODUCTION(PRODUCTION_DATE,MONTH_CODE ,FIN_YEAR_CODE, MATERIAL_CODE,APPROVED_QUANTIY,EXPECTED_QUANTITY)
VALUES (TO_CHAR(:ND_TRANSACTION.TRANSACTION_DATE,'DD\MM\YYYY'),TO_NUMBER(TO_CHAR(:ND_TRANSACTION.TRANSACTION_DATE,'MM')),V_YEAR_CODE,I.MATERIAL_CODE,I.EXPECTED_QUANTITY,I.EXPECTED_QUANTITY);
:SYSTEM.MESSAGE_LEVEL := 25;
COMMIT;
:SYSTEM.MESSAGE_LEVEL := 0;
END LOOP;


SET_BLOCK_PROPERTY('PLN_DAILY_PRODUCTION',DEFAULT_WHERE,'PRODUCTION_DATE = '||''''||TO_CHAR(:ND_TRANSACTION.TRANSACTION_DATE,'DD\MM\YYYY')||''''||' ');
EXECUTE_QUERY;


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the problem of this code is that it raise an exception; FRM-40735:when-new-block- instance raised unhandeled exception ORA0001 ,even if the record not exist
and can't make excute query can any one help pls...?

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Regards,


Abdetu..