lisp(defun mac-switch-meta nil 
  "switch meta between Option and Command"
  (interactive)
  (if (eq mac-option-modifier nil)
      (progn
    (setq mac-option-modifier 'meta)
    (setq mac-command-modifier 'hyper)
    )
    (progn 
      (setq mac-option-modifier nil)
      (setq mac-command-modifier 'meta)
      )
    )
  )