Hi Naomi, I have changed the code and put the rlock() and it seems to work fine. Thank you for your help. Cheers. Shafid

IF USED("barcno")
	USE IN barcno
ENDIF
IF NOT USED("barcno")
	SELECT 0
	USE barcno
endif		
select barcno 

nBarc=barcno.barcno  
IF nBarc <= 0
	MESSAGEBOX("This computer is not setup with barcode numbers","")
	RETURN
ENDIF 
IF RLOCK('barcno')	
	replace barcno with nBarc+1
	UNLOCK
else 
       MESSAGEBOX("The barcodes numbering file is in use, plese try again","")
	RETURN
ENDIF 	
FLUSH in barcno force
IF USED("barcno")
	USE IN barcno
ENDIF