Putting a image on the Gtk::Button..?

[sankar bose <shankarbose imp gmail com>]

Hi
 i have  a small question . Recently i experimented with some  code to put a image into a button, my code is given below..

Gtk::Image *m_image=new Gtk::Image("gtk-paste.png");
m_Button->set_image_position(Gtk::POS_LEFT);
m_Button->set_image(*m_image);
m_image->show();
show_all_children();

                                    At first the image did not show up at all. i hoped that the calling the show_all_children() was enough to display the all children but i fixed the problem when i called the show method of the image object .My question is that why do i have to call the show method isn't calling show_all_childer() enough to display all children ? .

                                         i am a newcomer to c++ and gtkmm, i have never programed gtk+ before so i dont know anything about gtk+ so i am very sorry if there is a easy explanation to this.
   

                                                                with regards........