As I read it (and I did run the code), the first run does not remove the form, indicating that it is a pass by VALUE while the second run is indeed a pass by reference. So, apparently objects (no, better: object references) are not always passed by reference, but can also be passed by value. Is this confusing?

>Peter, et al
>
>Objects are always passed by reference. The memvars pointing to them may or may not be passed by reference. A subtle difference:
>
>

>oform = createobject( "form" )
>oform.Visible = .t.
>
>callfunc( oForm, "test" )
>
>callfunc( @oForm, "test2" )
>
>function callfunc( loObject, lcCaption )
>
>loObject.Caption = lcCaption
>set step on
>loObject = .null.
>set step on
>return
>

>
>In both cases we can manipulate the object itself by changing the caption. but the first call does not result in the form disappearing. The second one does because the loObject = .null. line is actually affecting the oForm memvar not the form itself.
>
>>Pass thisform by reference, change its value and see what happens when you use it. See Re: Find a flaw in the logic Thread #1086027 Message #1086509