(s:input 'type "submit"   'name "form-name" 'value "login"))

(s:get-input 'email-address)

To preserve the input simply do a set of the value on the 'name field:
(s:set! "email-address" "matt@kiatoa.com")

Radio buttons:

	(s:div 'class "col_3"
		       (s:input 'type "radio" 'id "group-type1" 'name "group-type" 'value "private" 'checked "checked")
		       (s:label 'for "group-type1" 'class "inline" "Private")
		       (s:input 'type "radio" 'id "group-type2" 'name "group-type" 'value "public")
		       (s:label 'for "group-type2" 'class "inline" "Public"))

       (s:get-input 'group-type) ==> returns private or public depending on which is selected.

     (cons header pagedat))))

(define (session:log self . msg)
  (with-output-to-port (sdat-get-log-port self) ;; (sdat-get-logpt self)
    (lambda () 
      (apply print msg))))

;; escape, convert or return raw when given user input data that potentially
;; could be malicious
;;
(define (session:apply-type-preference res params)
  (let* ((dtype    (if (null? params)
		       'escaped
		       (car params)))
	 (tags    (if (null? params)
		      '()
		      (cdr params))))
    (case dtype
      ((raw)     res)
      ((number)  (if (string? res)(string->number res) #f))
      ((escaped) (if (string? res)
		     (s:html-filter->string res tags)
		     res))
      (else      (if (string? res)
		     (s:html-filter->string res '())
		     res)))))

(define (session:get-param self key type-params)
  ;; (session:log s:session "params=" (slot-ref s:session 'params))
  (let* ((params (sdat-get-params self))
	 (res    (session:get-param-from params key)))
    (session:apply-type-preference res type-params)))

;; This one will get the first value found regardless of form
;; param: (dtype [tag1 tag2 ...])
;; dtype:
;;    'raw     : do no conversion
;;    'number  : convert to number, return #f if fails
;;    'escaped : use html-escape to protect the input -- this is the default

	(if (and (vector? formdat)(eq? (vector-length formdat) 1)(hash-table? (vector-ref formdat 0)))
	    (formdat:keys formdat)
	    (begin
	      (session:log self "ERROR: formdat: " formdat " is not of class <formdat>")
	      #f)))))

(define (session:run-actions self)
  (let* ((action    (session:get-param self 'action '(raw)))
	 (page      (sdat-get-page self)))
    ;; (print "action=" action " page=" page)
    (if action
	(let ((action-lst  (string-split action ".")))
	  ;; (print "action-lst=" action-lst)
	  (if (not (= (length action-lst) 2)) 
	      (err:log "Action should be of form: module.action")

  (if (null? partsl)
      (session:call s:session page #f)
      (session:call s:session page (car partsl))))

(define (s:link-to page . params)
  (session:link-to s:session page params))

(define (s:get-param key . type-params)
  (session:get-param s:session key type-params))

;; these are page local
(define (s:get key) 
  (session:page-get s:session key))

(define (s:set! key val)
  (session:curr-page-set! s:session key val))