how to know the next value to be inserted STATEMENT_LINE_ID

Dear All,

im trying to manually insert a new record into CE_STATEMENT_LINES

but i got this error :

ORA-01400: cannot insert NULL into

("CE"."CE_STATEMENT_LINES"."STATEMENT_LINE_ID")

Procedure that im using:

CREATE OR REPLACE PROCEDURE XX_CE_PROCEDURE_AUDI

--(errbuf OUT VARCHAR2, retcode OUT NUMBER )

AS

C_AUDI_REC XX_ST_AUDI_LOAD%ROWTYPE;

ST_HEADER CE_STATEMENT_HEADERS.STATEMENT_HEADER_ID%type;

f_pay  CE_STATEMENT_LINES.TRX_TYPE%type;

K Number :=0;

CURSOR C_AUDI is

SELECT * from XX_ST_AUDI_LOAD where rownum =1;

BEGIN

OPEN C_AUDI ;

LOOP

FETCH C_AUDI into C_AUDI_REC;