Adding widgets to a vector class/Unknown amount of widgets in a window

[krampenschiesser freenet de]

Hi, 
I want to create a window with an unknown amount of buttons and scales.
Therefore I created a vector<Gtk::Button> buttons;
The Button I wanted to add was:
Gtk::Button btn("hello");
but compiling 
buttons.push_back(btn);
failed because something with the constructor and = was private.
Do you have any idea how I could solve this problem?
thx Christian

-- 
Everything should be made as simple as possible, but not simpler.
		-- Albert Einstein