setq first 5 )
(setq second 4)

(defun test ()
"compare first and second, and change large or small."
 (cond
  ((> first  second) (setq second (+  second first)) "hello")
  ((<= first second) (setq second (-  second first)) "goodbye")))

(test)
"hello"

"goodbye"


(defun cj2pre()
  "eval and return cursor."
  (interactive)
  (eval-print-last-sexp)
  (previous-line 2)
  (move-end-of-line 1)
  (global-set-key "\C-l" 'cj2pre))