>Hi everybody,
>
>I have a problem, which seems to me have no solutions.
>
>I have a logical field, which I want to populate with .t. on some condition and leave blank otherwise.
>
>I have to create this field using IIF expression:
>LogicalFiled=IIF (somecondition,.t.,.f.)
>
>My question is: How can I make this field blank, if !somecondition?

  Blank Fields TheAlias.TheLogicalField for !SomeCondition

But for most of the time you'll have the blanked field taken for a .f. value, unless you're specifically checking it with IsBlank(TheLogicalField). I've just tried this:

create curs yy (l l)
appe blank
?isblank(l)
appe blank
repl l with .f.
count for isblank(l)
?_tally
count for !isblank(l)
?_tally
count for l
?_tally
count for !l
?_tally

and it behaves as (I) expected.