ELisp refactoring tools

(defun create-new-function (function-name)
  "Creates a new function definition, given a selection. Removes
  the selection and replaces it with a call to the newly created function"
  (interactive "sFunction name: ")
  (let ((code (get-region)))
    (progn
      (save-excursion
        (progn
          (move-to-empty-point)
          (insert-new-function-definition function-name code)))
      (insert "(" function-name " )"))))