(define-page "/pong"
  (lambda ()
    (string-append "pong: " ($ 'rv #f))))

(define-page "/ping"
  (lambda ()
    `(form (@ (action "/pong")
	      (method "post"))
	   (input (@ (type "text")
		     (id "rv")
		     (name "rv")
		     (default "foo")))
	   (input (@ (type "submit")
		     (value "pingpong")
		     (class "button"))))))