Fullscreen in emacs 23

From: http://www.emacswiki.org/emacs/FullScreen

The following should work in Emacs 23:

   (defun toggle-fullscreen (&optional f)       (interactive)       (let ((current-value (frame-parameter nil 'fullscreen)))            (set-frame-parameter nil 'fullscreen                                 (if (equal 'fullboth current-value)                                     (if (boundp 'old-fullscreen) old-fullscreen nil)                                     (progn (setq old-fullscreen current-value)                                            'fullboth)))))

   (global-set-key [f11] 'toggle-fullscreen)

   ; Make new frames fullscreen by default. Note: this hook doesn't do     ; anything to the initial frame if it's in your .emacs, since that file is     ; read _after_ the initial frame is created.     (add-hook 'after-make-frame-functions 'toggle-fullscreen)