(defvar my-mh-init-done nil "Non-nil when one-time mh-e settings have made.")

(defun my-mh-folder-mode-hook ()
  "Hook to set key bindings in MH-Folder mode."
  (if (not my-mh-init-done)		; only need to bind the keys once 
      (progn
        (local-set-key "/" 'search-msg)
        (local-set-key "b" 'mh-burst-digest)	; better use of b
        (setq my-mh-init-done t))))

(add-hook 'mh-folder-mode-hook 'my-mh-folder-mode-hook)

(defun search-msg ()
  "Search for a regexp in the current message."
  (interactive)				; user function
  (other-window 1)			; go to next window
  (isearch-forward-regexp)		; string search; hit return (ESC in
					;   Emacs 18) when done
  (other-window -1))			; go back to folder