(defun monochrome-mode (&optional inverse-video)
  "Set up Emacs version 19 for editing on a monochrome system, with
transient marked regions enabled.  This will select a white background
with black foreground, cursor, and mouse.  With an argument, these
colors are reversed.

This function has no effect on older versions of Emacs, or when Emacs
is not running under a window system."
  (interactive "P")
  (if (string-equal (substring emacs-version 0 2) "19")
      (progn
	(let ((black (if inverse-video "white" "black"))
	      (white (if inverse-video "black" "white")))
	  (transient-mark-mode t)
	  (set-background-color white)
	  (set-foreground-color black)
	  (set-cursor-color black)
	  (set-mouse-color black)
	  (set-face-background (quote default) white)
	  (set-face-background (quote region) black)
	  (set-face-foreground (quote default) black)
	  (set-face-foreground (quote region) white)))))