+ add navigation links

+ typo corrected

scheme/httpd/surflets/web-server/root/surflets/spaceship.scm

@@ -319,7 +319,8 @@
 	    (td "My spaceship's drive is ")
 	    (td (table ,@(table-radios drive-radios drives))))
 	(tr))
-       ,(make-submit-button "Submit choices")))))
+       ,(make-submit-button "Submit choices"))
+     ,(return-links main-return-link))))
 
 ;;; Size page HTML.
 (define (generate-size-page new-url update-text class size-input)
@@ -337,7 +338,8 @@ fullfill UFP Spaceship Crew's Rights Act 023/1000285.0/AB")
 	(tr (td "My ship is for a crew of ")
 	    (td ,size-input)
 	    (td "people"))
-	(tr (td ,(make-submit-button))))))))
+	(tr (td ,(make-submit-button)))))
+     ,(return-links main-return-link first-page-return-link))))
 
 ;;; Text displayed if crew size is too big for the spaceship's class.
 (define (complain-size class size)
@@ -379,7 +381,8 @@ specify a positive number.")
 	      (p "Please specify the amount of energy you want to spent for your shields:")
 	      (table (tr (td ,shield-input) (td "TJ"))))
 	    '(h2 "Step 4 -- Done: No shields"))
-       ,(make-submit-button "OK")))))
+       ,(make-submit-button "OK"))
+     ,(return-links main-return-link first-page-return-link))))
 
 ;;; Text displayed, if arms' energy is not positive.
 (define positive-energy 
@@ -429,7 +432,8 @@ specify a positive number.")
 		  extras))
 	  (servlet-form ,new-url
 	    POST
-	    ,(make-submit-button "Order now")))))
+	    ,(make-submit-button "Order now"))
+	  ,(return-links main-return-link first-page-return-link))))
 
 ;;; HTML page generator for the extras page.
 ;;; Shows a list of possible extras of this spaceship class for selection.
@@ -439,14 +443,15 @@ specify a positive number.")
     (body
      (h2 "Step 5 -- Extras")
      (p "Select one or more extras that are available for
-spaceships of class " ,class)
+spaceships of class " ,class ":")
      (servlet-form ,new-url
        GET
        (table ,@(map (lambda (checkbox+text)
 		       `(tr (td ,(car checkbox+text))
 			    (td ,(cdr checkbox+text))))
 		     checkboxes+text))
-       ,(make-submit-button "OK")))))
+       ,(make-submit-button "OK"))
+     ,(return-links main-return-link first-page-return-link))))
 			      
 ;;; HTML page generator. 
 ;;; Shows the final page with a "Thank you" and an estimate for the
@@ -460,7 +465,23 @@ spaceships of class " ,class)
 		  "We will contact you (" 
 		  ,(host-name-or-ip (socket-remote-address (request-socket req)))
 		  ") as soon as the ship is built.")
-	       (p "This will take about " ,months " months."))))
+	       (p "This will take about " ,months " months.")
+	       ,(return-links main-return-link first-page-return-link))))
+
+(define main-return-link
+  '(URL "/" "Return to main menu."))
+
+(define (previous-page-return-link prev)
+  `(URL ,prev "Return to previous page."))
+
+(define first-page-return-link
+  '(URL "/servlet/spaceship.scm" "Return to spaceship builder entry page."))
+
+(define (return-links . links)
+  `(p
+    (hr)
+    ,@(map (lambda (link) (list link '(br)))
+	   links)))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Helping functions