Index: openacs-4/packages/xowiki/tcl/includelet-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/includelet-procs.tcl,v
diff -u -r1.239.2.54 -r1.239.2.55
--- openacs-4/packages/xowiki/tcl/includelet-procs.tcl	9 Sep 2020 10:24:37 -0000	1.239.2.54
+++ openacs-4/packages/xowiki/tcl/includelet-procs.tcl	28 Sep 2020 21:04:04 -0000	1.239.2.55
@@ -3609,7 +3609,7 @@
   graph instproc graphHTML {-edges -nodes -max_edges -cutoff -base {-attrib node_id}} {
 
     ::xo::Page requireJS "/resources/ajaxhelper/prototype/prototype.js"
-    set user_agent [string tolower [ns_set get [ns_conn headers] User-Agent]]
+    set user_agent [string tolower [ns_set iget [ns_conn headers] User-Agent]]
     if {[string match "*msie *" $user_agent]} {
       # canvas support for MSIE
       ::xo::Page requireJS "/resources/xowiki/excanvas.js"