GTK-- question (newbie)

[Tom Fishwick <tfishwick coastnet com>]

Hi, 
        I'm using Gtk-- (on linux), and am trying to insert text into
'Gtk_Text'.  I've connected Gtk_Text::changed() to a method that inserts
some text, and it works fine.  But when I tried doing this
'MyGtkText.insert(0, 0, 0, "gg", 2)' inside a method thats connected to
Gtk_FileSelection.ok_button.pressed then it gives me

** WARNING **: invalid class type `(unknown)' in cast to `GtkText'

** WARNING **: file gtktext.c: line 694 (gtk_text_insert): "GTK_IS_TEXT
(text)" 
        
What does this mean?  I have to somehow cast the object?  Or put the
widget in focus?

BTW, I'm fairly new to c++ and gtk...  so please take it easy on me if
this is a dumb question :-).
Thanks for any help!
-- 
Tom
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