Need help with Stored Procedure

Hi

I am kinda new at this...I have the Following Stored Procedure

*****************
CREATE PROCEDURE NROSWI.AMEND_EVENT ( P_EVENT_ID INT, P_MODE INT, P_REASON VARCHAR(254), P_TERMINATION_DATE DATE, P_USER_ID INT)
SPECIFIC NROSWI.AMEND_EVENT
------------------------------------------------------------------------
-- SQL Stored Procedure
------------------------------------------------------------------------
P1: BEGIN
DECLARE CONSTANT_AMEND_CODE_ID INT;
DECLARE CONSTANT_CANCEL_CODE_ID INT;
DECLARE NEW_EVENT_ID INT;

SET NEW_EVENT_ID = NEXT VALUE FOR NROSWI.EVENT_SEQ;
SET CONSTANT_AMEND_CODE_ID = 54;
SET CONSTANT_CANCEL_CODE_ID = 56;


FOR L1 AS SELECT
NRCSWAP_APPLICATION_ID, NRCSWCT_EVENT_CODE_ID, NRCSWEV_NO_SEQUENCE,
NRCSWDP_DIST_PRACT_ID, NRCSWCT_LIFESPAN_CODE_ID,
NRCSWCT_INSTALLED_UNIT_CODE_ID,
NRCSWMX_MAXIMUM_ID, NRCSWAG_ALLOCATION_GROUP_ID,
NRCSWCT_RECONSTRUCTION_CODE_ID
...
FROM NROSWI.NRTSWI_EVENT
WHERE NRCSWEV_EVENT_ID = P_EVENT_ID DO

INSERT INTO
NROSWI.NRTSWI_EVENT (NRCSWEV_EVENT_ID, NRCSWAP_APPLICATION_ID,
NRCSWCT_EVENT_CODE_ID, NRCSWEV_NO_SEQUENCE,
NRCSWDP_DIST_PRACT_ID, NRCSWCT_LIFESPAN_CODE_ID,
NRCSWMX_MAXIMUM_ID, NRCSWAG_ALLOCATION_GROUP_ID, ...)
VALUES (NEW_EVENT_ID, L1.NRCSWAP_APPLICATION_ID,
CASE P_MODE WHEN 0 THEN CONSTANT_AMEND_CODE_ID ELSE
CONSTANT_CANCEL_CODE_ID END,
L1.NRCSWEV_NO_SEQUENCE + 1,
L1.NRCSWDP_DIST_PRACT_ID, L1.NRCSWCT_LIFESPAN_CODE_ID,
L1.NRCSWMX_MAXIMUM_ID, L1.NRCSWAG_ALLOCATION_GROUP_ID, ....);
END FOR;
*****************

Problem is I need to get the maximum number from the NRCSWEV_NO_SEQUENCE and then +1 with it when i am inserting instead of L1.NRCSWEV_NO_SEQUENCE..

Can any one Help please