what does 'eval-after-load' what 'add-hook' doesn't do?

[Leo]

hi there

in for xemacs i want to bind a key in the dired-mode-map:

i tried:

(add-hook 'dired-load-hook
   (lambda ()
     '(define-key dired-mode-map "j" 'w32-shellex-dired-on-objects)
   ))

that doesn't work.

now i found:

(eval-after-load
    "dired"
  '(define-key dired-mode-map "j" 'w32-shellex-dired-on-objects))

what works fine.

but why???

ta for any help, leooo