beginner's question:add-hook&AUCTeX

[Shiyuan]

Hi, 
    I want to swap the C-j and C-m key. According to the documentation, AUCTeX will evaluate the LaTeX-mode-hook so I add the following to my .emacs,

(add-hook 'LaTeX-mode-hook (lambda()
                 (local-set-key (kbd "C-m") 'reindent-then-newline-and-indent)))
(add-hook 'LaTeX-mode-hook (lambda()
                 (local-set-key (kbd "C-j") 'newline)))

However, it has no effect. It seems it's not evaluated at all. Any help is appreciated. 

Gu.