anchor.diff:  
       ;; when the window bgcolor is removed, the background simple-char is displayed instead of spaces
       (setf (bgcolor scr) nil)
  +    (format scr "color-pair nil | background blue on white~%") (refresh scr) (get-char scr)
  +
  +    (setf (fgcolor scr) nil
  +          (bgcolor scr) nil)
  +    (setf (background scr) (make-instance 'complex-char :simple-char #\. :color-pair '(:white :red)))
       (format scr "color-pair nil | background blue on white~%") (refresh scr) (get-char scr)))
   
   (defun t31c ()
  
positive.code:                (loop for i from 0 to 5 collect
                   (make-instance 'label :active nil :border t :padding 1
                                         :title (format nil "hello ~r" (random 20))))))
             (form (make-instance 'form
                                  :window scr
                                  ;; instead of passing the elements in a element list, pass them within a layout object.
                                  ;; this will automatically calculate their positions during form initialization.
                                  ;; "nil" elements are represented as empty cells in the grid.
                                  :layout (make-instance 'layout ;;:grid-rows 3
                                                                 :grid-columns 3
                                                                 :grid-gap '(1 2) :position '(2 4)
                                                                 :children (append (list menu1 nil) buttons (list area nil labels1 nil field)))
                                  :style '(field (:background (:attributes (:reverse))
                                                  :selected-background (:bgcolor :blue))
                                           textarea (:background (:attributes (:reverse))
                                                     :selected-background (:bgcolor :blue))
                                           label (:foreground (:fgcolor :red :bgcolor :yellow)
                                                  :background (:fgcolor :yellow :bgcolor :red)
                                                  :border (:fgcolor :red :bgcolor :yellow)
  
negative.code: (defun t16e4 ()
    "Initially, the buffer of the textarea is just a list of characters.
  
  For small buffer sizes, this is sufficient, but at some later point,
  it will be more efficient to use a character array, a string."
    (with-screen (scr :input-echoing nil :cursor-visible t :enable-colors t :enable-function-keys t :input-blocking t)
      (let ((area (make-instance 'textarea :position '(5 5) :dimensions '(3 20) :window scr
                                 :buffer (concatenate 'list
  