The Error : "File is in Use by Another User"

How it occurs....

I have a File I call "AuditBat" which has the code below... it is called by various Batch Files that run during the day and night... and some start at the SAME TIME...

Here is AuditBat code..

*****************************************************************************

PARAMETERS psProgName, psStatus, pdStartDate, psStartTime

IF TYPE('psProgName') # 'C'
	RETURN
ENDIF
IF TYPE('psStatus') # 'C'
	RETURN
ENDIF
IF TYPE('pdStartDate') # 'D'
	RETURN
ENDIF
IF TYPE('psStartTime') # 'C'
	RETURN
ENDIF

LOCAL lcExclusive
STORE SET('EXCLUSIVE') TO lcExclusive
SET EXCLUSIVE OFF

IF NOT USED('auditbat')
	USE \\rsvpsource\wrktest\programs\auditbat IN 0 ALIAS auditbat SHARED
ENDIF
SELECT auditbat

IF UPPER(ALLTRIM(psStatus)) = 'START'
	INSERT INTO auditbat (progname,   startdate,   starttime) ;
	       VALUES        (psProgName, pdStartDate, psStartTime)
ELSE
	IF UPPER(ALLTRIM(psStatus)) = 'END'
	UPDATE auditbat	SET EndDate = DATE(), EndTime = TIME() ;
	  WHERE Progname = psProgName AND StartDate = pdStartDate AND StartTime = psStartTime
	ENDIF
ENDIF

SELECT auditbat
USE

SET EXCLUSIVE &lcExclusive
RETURN

*********************************************************************************

The error occurs in line 48

	INSERT INTO auditbat (progname,   startdate,   starttime) ;
	       VALUES        (psProgName, pdStartDate, psStartTime)
ELSE

*********************************************************************************

Most of the time, there is NO error...and there are 2 batch programs that ususally start at the SAME TIME, and most of the time, there is no ERROR... but once in a while there is.

I noticed that I caused an error today when I opened the AUDITBAT and ERRLOG table in SHARED mode, and whatched what would happend at 11:30 this morning when both batch files started to run.... an ERROR occured!

Any ideas? Sharing vs Exclusive mode for the INSERT and UPDATE commands??

Thanks for any ideas!

Tommy