Failed to customize a local key-binding in GDB mode in GNU Emacs 23

Question

I've added the code below to my .emacs to bind the command gdb-restore-windows to the key sequence C-c C-.. But when I start GDB mode and type the key sequence, I always get the prompt

C-c C-. is undefined.

(defun xyt/gdb-hotkey-hook ()
  (local-set-key (kbd "C-cC-.") 'gdb-restore-windows))

(add-hook 'gdb-mode-hook 'xyt/gdb-hotkey-hook)

Answer 1

As @artscan pointed out in the questions' comment, I had missing a space.