How to prevent accidental iconification in Emacs

gistfile1.el

;;; This is taken from planet Emacsen: http://tsengf.blogspot.com/2011/06/prevent-accidental-iconify-of-emacs.html.
;;; I've added a check to see if we're on a graphic environment.

;;; Prevent acidental iconify/suspend.
(when (window-system) 
  (defun smart-iconify-or-deiconify-frame ()
    "Present a confirmation before suspending/iconifying."
    (interactive)
    (if (yes-or-no-p (format "Are you sure you want to iconify/deiconify Emacs? "))
        (iconify-frame)))
  ;; Rebinding C-z to the new function.
  (global-set-key (kbd "C-z") 'smart-iconify-or-deiconify-frame)
  ;; Rebinding C-x C-z to the new function. Overrides suspend-frame.
  (global-set-key (kbd "C-x C-z") 'smart-iconify-or-deiconify-frame)))