--- a/.emacs-my	Wed Sep 01 16:33:09 2010 +0300
+++ b/.emacs-my	Fri Sep 03 16:32:14 2010 +0300
@@ -448,13 +448,22 @@
 ;; ----------------------------------------------------------------------
 ;; dired.
 
+(require 'dired)
+
 (setq dired-dwim-target t)
 ;; dangerous
 ;; (setq
 ;;  dired-recursive-copies 'top
 ;;  dired-recursive-deletes 'top)
 
-(put 'dired-find-alternate-file 'disabled nil) ; Enable 'a' command.
+(when (>= emacs-major-version 22)
+  ;; Enable 'a' command.
+  (put 'dired-find-alternate-file 'disabled nil)
+  (define-key dired-mode-map (kbd "<return>")
+    'dired-find-alternate-file)
+  (define-key dired-mode-map (kbd "<backspace>")
+    (lambda () (interactive) (find-alternate-file "..")))
+  )
 
 ;; ----------------------------------------------------------------------
 ;; compression, archive.