Index: openacs-4/packages/calendar/tcl/calendar-display-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/calendar/tcl/Attic/calendar-display-procs.tcl,v
diff -u -r1.23 -r1.24
--- openacs-4/packages/calendar/tcl/calendar-display-procs.tcl	15 May 2002 22:34:57 -0000	1.23
+++ openacs-4/packages/calendar/tcl/calendar-display-procs.tcl	15 May 2002 23:37:49 -0000	1.24
@@ -312,6 +312,11 @@
         if {[empty_string_p $calendar_id_list]} {
             set calendar_id_list [list [calendar_have_private_p -return_id 1 [ad_get_user_id]]]
         }
+
+        # sort by cannot be empty
+        if {[empty_string_p $sort_by]} {
+            set sort_by "item_type"
+        }
         
         set date_format "YYYY-MM-DD HH24:MI"
         set current_date $date