cscope - setup

Here is the setting in my .emacs

(require 'xcscope)
(setq cscope-do-not-update-database t)
(setq cscope-initial-directory "/path/of/src")

(define-key global-map [(ctrl f3)] 'cscope-set-initial-directory)
(define-key global-map [(ctrl f4)] 'cscope-unset-initial-directory)
(define-key global-map [(ctrl f5)] 'cscope-find-this-symbol)
(define-key global-map [(ctrl f6)] 'cscope-find-global-definition)
(define-key global-map [(ctrl f7)]
'cscope-find-global-definition-no-prompting)
(define-key global-map [(ctrl f8)] 'cscope-pop-mark)
(define-key global-map [(ctrl f9)] 'cscope-next-symbol)
(define-key global-map [(ctrl f10)] 'cscope-next-file)
(define-key global-map [(ctrl f11)] 'cscope-prev-symbol)
(define-key global-map [(ctrl f12)] 'cscope-prev-file)
(define-key global-map [(meta f9)] 'cscope-display-buffer)
(define-key global-map [(meta f10)] 'cscope-display-buffer-toggle)