(when (version< emacs-version "24.4")
  (defun define-error (name message &optional parent)
    "Define NAME as a new error signal.
MESSAGE is a string that will be output to the echo area if such an error
is signaled without being caught by a `condition-case'.
PARENT is either a signal or a list of signals from which it inherits.
Defaults to `error'."
    (unless parent (setq parent 'error))
    (let ((conditions
           (if (consp parent)
               (apply #'nconc
                      (mapcar (lambda (parent)
                                (cons parent
                                      (or (get parent 'error-conditions)
                                          (error "Unknown signal `%s'" parent))))
                              parent))
             (cons parent (get parent 'error-conditions)))))
      (put name 'error-conditions
           (delete-dups (copy-sequence (cons name conditions))))
      (when message (put name 'error-message message)))))