David,
I created a slightly different version of your UDF, since I don't want the call to the UDF to error if the property/variable doesn't exist. Here's what I have now, FYI. Thanks again!

* IsObj.prg
* Test if passed property/variable name is an object.

LPARAMETERS m.tcObj

RETURN TYPE(m.tcObj) = "O" AND NOT ISNULL(EVALUATE(m.tcObj))

-Mark

>Mark,
>
>I use a UDF IsObject() to perform the test:
>
>

>lparameter roObject
>
>return( ( type( "m.roObject" ) == 'O' ) and ( ! isnull( m.roObject ) ) )
>