How to resolve the error

FORM fetch_data.

* MESSAGE 'An error occurred during data fetch.' TYPE <TYPE>.
IF P_RB1 = 'X'.
SELECT TRANSACTION_DATE TRANSACTION_ID TRANSACTION_AMOUNT CURRENT_BALANCE CURRENCY
FROM Z019_ACCOUNT AS AC INNER JOIN Z019_TRANSACTION AS TR
ON AC~ACCOUNT_NUMBER = TR~TO_ACC_NO INTO CORRESPONDING FIELDS OF TABLE GT_OUT
WHERE AC~ACCOUNT_NUMBER IN S_ACCNO.

ELSEIF P_RB2 = 'X'.
SELECT TRANSACTION_DATE TRANSACTION_ID TRANSACTION_AMOUNT CURRENT_BALANCE CURRENCY
FROM Z019_ACCOUNT AS AC INNER JOIN Z019_TRANSACTION AS TR
ON AC~ACCOUNT_NUMBER = TR~FROM_ACC_NO INTO CORRESPONDING FIELDS OF TABLE GT_OUT
WHERE AC~ACCOUNT_NUMBER IN S_ACCNO.

IF SY-SUBRC <> 0.
MESSAGE 'An error occurred during data fetch.' TYPE 'E'.
ENDIF.
ENDIF.

ENDFORM.

ERROR : S_ACCNO is not an internal table