--- a/Cookbook/menu.html	Mon Sep 13 12:33:12 2021 +0100
+++ b/Cookbook/menu.html	Fri Apr 08 17:05:57 2022 +0100
@@ -25,7 +25,7 @@
 </tr>
 
 <tr>
-<td style="background-color: rgb(224, 224, 240);"> <IMG SRC="new.gif" ALT="" style="" align="left"><a href="http://talisker.nms.kcl.ac.uk/cgi-bin/repos.cgi/isabelle-cookbook/raw-file/tip/progtutorial.pdf" onclick="pageTracker._trackPageview('tutorial');" target="_top">
+<td style="background-color: rgb(224, 224, 240);"> <IMG SRC="new.gif" ALT="" style="" align="left"><a href="https://talisker.nms.kcl.ac.uk/cgi-bin/repos.cgi/isabelle-cookbook/raw-file/tip/progtutorial.pdf" onclick="pageTracker._trackPageview('tutorial');" target="_top">
 Latest Draft</a>  (updated to Isabelle 2019 thanks to Norbert Schirmer)<BR><BR><BR></td>
 </tr>