(define (set-usage-extra m)
  (let ((h (/ m 60)))
    (setf m (- m (* h 60)))
    (write-file EXTRAFILE (format "%d %d\n" h m))))

(catch
    (let ((data "")(b "") (c '()) (v nil))
      (while (read 0 b 1000) (extend data b))
      (setf v (map (fn (x) (parse x "=")) (parse data "&")))
      (set-usage-extra (int (or (lookup "minutes" v) "0") 0 10))))

"usage-extra.lsp"