class menu_bar : public menubar {          // row of menubuttons 
    public:
      menu_bar(widget* w, tablet* t, toolbox* b) : menubar(w,"bar") { 
        configure("-relief sunken"); 
    
        menubutton* b1 = new file_menu(this,t); 
        menubutton* b2 = new edit_menu(this,b);
        button* b3 = new help_button(this); 
      }
    };