Help: Stored Procedure Woes

Greetings,

I am trying to figure out what is wrong with the following stored procedure. It compiles without any errors; however, the procedure fails with the following
error whenever VALUE has more that one character in it. Also, will SET TRANSACTION ISOLATION LEVEL SERIALIZABLE ensure concurrency is not violated during this stored procedure.

ORA-06502: PL/SQL: numeric or value error ORA-06512: at "XIPAY.INC_MIT", line 9

Here is the stored procedure. Thanks in advance to anyone that can assist me with this problem. Please send replies to : james.williams_at_xitc.com

CREATE OR REPLACE PROCEDURE TEST.INC_MIT (sName in VARCHAR2, sDefaultValue in out VARCHAR2) is
  nTotalRows NUMBER;
BEGIN
  SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;   SELECT COUNT(NAME) INTO nTotalRows FROM TEST.MISC_INFO WHERE NAME = sName;  IF nTotalRows = 0 THEN

    INSERT INTO TEST.MISC_INFO (MISC_INFO_ID, NAME, VALUE, MOD_DATE) VALUES (MISC_INFO_ID_SEQ.NEXTVAL, sName, sDefaultValue, SYSDATE);  ELSE
   SELECT TO_CHAR(A.VALUE+1) INTO sDefaultValue FROM TEST.MISC_INFO A WHERE A.NAME = sName;
  UPDATE TEST.MISC_INFO SET VALUE = sDefaultValue where NAME = sName;  END IF;
 COMMIT;
END; Received on Wed Dec 13 2000 - 15:13:35 CST