>hi,
>i try as under, error message Invalid subscript reference
>

>CLOSE all
>*use answers excl
>select answers && excl - you can not put exclusive in SELECT command, it should be in the USE command
>local lnI as Integer, llError as Logical
>local array laFields[1]
>afields(laFields)

for lnI = 1 to alen(laFields,1)
  llError = .f.
>if inlist(laFields[m.lnI,2],'N','B','I')&&Invalid subscript reference
>   if not laFields[m.lnI,5] && &&Invalid subscript reference
>       try
>         ALTER TABLE MyTable  ALTER COLUMN (laFields[m.lnI,1]) NULL
>       catch to loError
>          llError = .t.
>       endtry
>   endif
>   if not m.llError
>       replace (laFields[lnI,1]) with null for empty(&laFields[lnI,1])
>   endif
>endif
endfor
>brow
>

Mohammad,

You forgot to add a loop. See the corrections and some comments inside your code.