Hello everyone! Org-mode is amazing. I've totally fallen in love with it. Glad to be joining the community. 

I'm trying to get org-mode to automatically mark DONE when all sub checkboxes are checked. On http://orgmode.org/worg/org-faq.html, I found a function that purports to do this.

I pasted the function into my .emacs file, but now I'm getting an error message when I launch: "Symbol's value as variable is void: org-checkbox-statistics-hook." 

Any thoughts? Thanks in advance! 


;; see http://thread.gmane.org/gmane.emacs.orgmode/42715
(add-to-list 'org-checkbox-statistics-hook (function ndk/checkbox-list-complete))

(defun ndk/checkbox-list-complete ()
  (save-excursion
    (org-back-to-heading t)
    (let ((beg (point)) end)
      (end-of-line)
      (setq end (point))
      (goto-char beg)
      (if (re-search-forward "\\[\\([0-9]*%\\)\\]\\|\\[\\([0-9]*\\)/\\([0-9]*\\)\\]" end t)
            (if (match-end 1)
                (if (equal (match-string 1) "100%")
                    ;; all done - do the state change
                    (org-todo 'done)
                  (org-todo 'todo))
              (if (and (> (match-end 2) (match-beginning 2))
                       (equal (match-string 2) (match-string 3)))
                  (org-todo 'done)
                (org-todo 'todo))))))))



P.S. Not sure if it's relevant, but I'm on OSX using Aquamacs 2.4.