newbie elisp question

[B. T. Raven]

With the following forms in my .emacs, which the *scratch* buffer
evaluates without complaint, (from which I infer that they are at least
syntactically correct)

(defconst *vowels* '(?a ?e ?i ?o ?u ?y)
  "A list of the English vowels in lowercase.")

...
(defun vowelp (char)
  (memq (downcase char) *vowels*))

(defun goto-vowel
"Skip to next vowel after point."
(interactive)
(while (not (vowelp (char-after))) (forward-char))
)

(define-key global-map [f11] 'goto-vowel)

...

I get this error message:

"call-interactively: Invalid function: (lambda "Skip to next vowel after
point." (interactive) (while (not (vowelp (char-after)))
(forward-char)))"

What am I not understanding here?

Thanks,

Ed