[Howm-eng 24] How to add my own action lock in howm?

[highfly22 at gmail.com (highfly22)]

Hi,
    I am try to do this, just like action lock between {*} {-} { }

(defvar priority-ring '("!H" "!M" "!L" "!-" "!H"))

(defvar priority-rule
      '("\\(!H\\|!M\\|!L\\|!-\\)[ \t]"
    (lambda
      (&optional dummy)
      (let*
          ((b
        (match-beginning 1))
           (e
        (match-end 1))
           (ring
        priority-ring)
           (s
        (match-string-no-properties 1))
           (next
        (cadr
         (member s ring))))
        (delete-region b e)
        (goto-char b)
        (insert next)
        (goto-char b))
      ) 0 ))

(defun gtd-action-lock()
  (action-lock-add-rules (list context-rule))
  )

(add-hook 'action-lock-mode-on-hook 'gtd-action-lock)

But it doesn't work, I don't know why?

And how can I add my action lock in howm-mode?

Thanks

Regards,
Highfly