Hi Mike,

>>I have to create this field using IIF expression:
>>LogicalFiled=IIF (somecondition,.t.,.f.)
>
>You do not need an IIF() if you are returning a .T. or a .F.
>
>LogicalValue = somecondition

Good point :) Thank you.
>
>>My question is: How can I make this field blank, if !somecondition?
>
>Why do you want to? If its blank its .f., but if you really really want to, I think you can use the BLANK command