Here is the complete code, (I start Hunchentoot from REPL and use parenscript)
(defpackage :ajax (:use :cl :hunchentoot :cl-who :parenscript :ht-simple-ajax)) (in-package ajax)
(setf *access-log-pathname* "c:/lisp/hunchentoot-log/access.log") (setf *message-log-pathname* "c:/lisp/hunchentoot-log/message.log")
(setf *js-string-delimiter* #")
(defparameter *ajax-processor* (make-instance 'ajax-processor :server-uri "/ajax"))
(defun-ajax say-hi (name) (*ajax-processor*) (concatenate 'string "Hi " name))
(define-easy-handler (main-page :uri "/") () (with-html-output-to-string (*standard-output* nil :prologue t :indent t) (:html :xmlns "http://www.w3.org/1999/xhtml" (:head (:title "ht-simple-ajax demo") (princ (generate-prologue *ajax-processor*)) (:script :type "text/javascript" (str (ps (defun callback (response) (alert (@ response firstChild firstChild nodeValue)))
(defun sayHi () (ajax_say_hi (chain document (getElementById "name") value) callback))))))
(:body (:p "Please enter your name: " (:input :id "name" :type "text")) (:p (:a :href "javascript:sayHi()" "Say Hi!"))))))