gtk_container_add (GTK_CONTAINER (window), main_vbox);
frame_horz = gtk_frame_new ("Horizontal Button Boxes");
gtk_box_pack_start (GTK_BOX (main_vbox), frame_horz, TRUE, TRUE, 10);
gtk_container_add (GTK_CONTAINER (window), main_vbox);
frame_horz = gtk_frame_new ("Horizontal Button Boxes");
gtk_box_pack_start (GTK_BOX (main_vbox), frame_horz, TRUE, TRUE, 10);