Why go half way?

Select NVL(max(itemnum), 0) from inspdata where jobnum==lnJobnum into array lnMaxItem
RETURN lnMaxItem[1]

Also if table/view is buffered it'll require

WITH (BUFFERING = .T.)

>It may not be related, but instead of Calculate, I would use a SQL Select statement instead, since it doesn't move the record pointer.
>

>IF !EOF('inspdata') AND !BOF('inspdata')
>   local lnjobnum
>   lnJobnum=inspheader.jobnum
>   Select max(itemnum) from inspdata where jobnum==lnJobnum into array lnMaxItem
>   RETURN lnMaxItem
>ELSE
>   Return 0
>endif

>