Post back your whole code. Do you use alen(laFields,1) in your loop? If yes, it should work.

>error message
>Invalid subscript reference
>if inlist(laFields[m.lnI,2],'N','I','B')
>>Try
>>

>>if inlist(laFields[m.lnI,2],'N','I','B') && Numeric, double or Integer
>>   replace ...
>>endif