doc/manual: Include screenshot of generic error message.

* doc/manual/Makefile.am (images): Add new file.
* doc/manual/firefox-bad-pin.png: New file.
* doc/manual/scute.texi: Update the paragraph on generic error
messages printed by Firefox, and include screenshot.

Signed-off-by: Justus Winter <justus@g10code.com>

doc/manual/Makefile.am

@@ -34,7 +34,7 @@ DISTCLEANFILES = scute.tmp
 images = firefox-cm.png firefox-cm-view-detail.png firefox-cm-view.png \
 	firefox-dm-load-after.png firefox-dm-load-before.png \
 	firefox-dm-load.png firefox-dm-token-present.png firefox-pref.png \
-	firefox-pref-view.png
+	firefox-pref-view.png firefox-bad-pin.png
 
 images_eps = $(images:.png=.eps)
 

doc/manual/scute.texi

@@ -543,11 +543,12 @@ the server.
 If the card is not present, or you enter the wrong PIN, or the server
 does not admit your certificate, you will get an error message.  This
 error message is generated by the application and Scute can not
-influence it.  Unfortunately, in Firefox 1, this error message is not
-very user friendly: ``@code{example.com has received an incorrect or
-unexpected message.  Error code: -12227}''.
+influence it.  Unfortunately, in Firefox (at least up to version
+38.5.0), this error message is not very user friendly.  For example,
+entering a bad PIN results in the following generic error message, and
+the @code{Try Again} button does not work as expected:
 
-FIXME: Screenshot.
+@center @image{firefox-bad-pin,11cm}
 
 FIXME: Document possible error codes.