/* modify your main function something like this... */
void main( void )
{
  GLint objMenu, matlMenu;

  .
  .
  .
  /* Most of your initialization and GLUT initialization goes here */
  .
  .
  .
  
  /* Object Menu */
  objMenu = glutCreateMenu( menuCallback );
  glutAddMenuEntry("(X) Al Capone", 200);
  glutAddMenuEntry("(  ) Stanford Bunny", 201);
  glutAddMenuEntry("(  ) Stanford Dragon", 202);
  glutAddMenuEntry("(  ) Utah Teapot", 203);

  /* Material menu */
  matlMenu = glutCreateMenu( menuCallback );
  glutAddMenuEntry("(X) Brass", 300);        //  <--- the number is the value passed to the menu callback
  glutAddMenuEntry("(  ) Pewter", 301);
  glutAddMenuEntry("(  ) Emerald", 302);
  glutAddMenuEntry("(  ) Black Plastic", 303);

  /* Main menu */
  glutCreateMenu( menuCallback );  
  glutAddSubMenu("Object Selection", objMenu );
  glutAddSubMenu("Material Selection", matlMenu );
  glutAddMenuEntry(" ", 0 );
  glutAddMenuEntry("Quit", 27);
  glutAttachMenu(GLUT_RIGHT_BUTTON);  // attaches the current menu to the right button 
                                      //   (the current one is the last one created!)
  
  .
  .
  .
  /* start yout glutMainLoop() down here */
  .
  .
  .
  
}




/* add menu callback a menu callback something like this... */
void menuCallback( int value )
{
  switch (value) 
    {
    default:
      break;
    case 200:  // User selected menu item "Al Capone".  Deal with it!
      break;
    case 201:  // User selected menu item "Stanford Bunny".  Deal with it!
      break;
    case 202:  // User selected menu item "Stanford Dragon".  Deal with it!
      break;
    case 203:  // User selected menu item "Utah Teapot".  Deal with it!
      break;
    case 300:  // User selected menu item "Brass".  Deal with it!
      break;
    case 301:  // User selected menu item "Pewter".  Deal with it!
      break;
    case 302:  // User selected menu item "Emerald".  Deal with it!
      break;
    case 303:  // User selected menu item "Black Plastic".  Deal with it!
      break;
    case 27:   // User selected "Quit"!
      exit(0);
      break;
    }

  glutPostRedisplay();
}