get this error when M-x erc-sitea or M-x my-irc : Wrong type argument : sequencep, :server


(require 'erc)


 (defmacro asf-erc-bouncer-connect (command server port nick ssl)
   "Create interactive command `command', for connecting to an IRC server. The
   command uses interactive mode if passed an argument."
   (fset command
         `(lambda (arg)
           (interactive "p")
	   (if (not (= 1 arg))
	       (call-interactively 'erc)
	     (let ((erc-connect-function ',(if ssl
					       'erc-open-ssl-stream
					     'open-network-stream)))
 	       (erc :server ,server :port ,port :nick ,nick))))))

  (autoload 'erc "erc" "" t)

 ;; non-ssl connection:
 (asf-erc-bouncer-connect erc-free "irc.site0.net" 6667 "hengha" nil)

 ;; ssl connection:
 (asf-erc-bouncer-connect erc-emc "irc.site1.net" 6667 "hengha" t)

 ;; fires up a new frame and opens your servers in there. You will need
 ;; to modify it to suit your needs.
 (defun my-irc ()
   "Start to waste time on IRC with ERC."
   (interactive)
   (select-frame (make-frame '((name . "Emacs IRC")
 			      (minibuffer . t))))
   (call-interactively 'erc-site0)
   (sit-for 1)
   (call-interactively 'erc-site1)
 )