next-line + recenter (- redraw frame)?

[Peter Tury]

Hi,

I've created a tiny function for ease reading:

(defun down-center ()
  "Moves point down by one line and then moves the line to the
center of the screen.
Keeps columns as next-line does.
Created for ease reading (of program source codes) (since this
way the user always can see the most lines around)."
  (interactive)       
  (if (eq last-command 'down-center)
      (setq last-command 'next-line))
  (next-line)
  (recenter))

(define-key global-map [M-down] 'down-center)

Please comment it!

I am especially interested in these:

- do you know some builtin function what does the same (=so this function
is totally unnecessary) in emacs 22?

- how could I get rid of setting last-command (it seems to be a quite ugly
solution for me...) (it is necessary if you go through e.g. an empty or too
short line: then, without this last-command setting, the original column is
lost (since next-line (more exactly: line-move-1) uses last-command :-((

- how could I get rid of redrawing the frame? recenter's doc writes: "Just
C-u as prefix means put point in the center of the window
and redisplay normally--don't erase and redraw the frame." -- I would like
to use this. But how to call recenter from elisp "just uing C-u as prefix"?
It seems for me that if I put "(universal-argument)" (what is bound to C-u)
before "(recenter)" it doesn't help.

Thanks,
P