Also, empdrvr.callboard needs to be a text expression -

IIF(type("empdrvr.callboard") = "L", empdrvr.callboard, empdrvr.callboard = 1)

-Dan

>>I am trying to build a controlsource for a checkbox that will work with two different possible sets of tables.
>>

>>IIF([type(empdrvr.callboard) = "L"], empdrvr.callboard, IIF([empdrvr.callboard = 1], .T., .F.))
>

>
>Sure, the brackets are interpreted as quotation marks.
>
>Change this:
>
>

>iif([...
>

>
>to this:
>
>

>iif(...)
>

>
>By the way, the second iif() is superfluous, just return empdrvr.callboard = 1, which is already true or false.
>
>This reduces the entire epxression to:
>
>

>IIF(type(empdrvr.callboard) = "L", empdrvr.callboard, empdrvr.callboard = 1)
>