Index: openacs-4/packages/acs-templating/tcl/tab-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-templating/tcl/tab-procs.tcl,v
diff -u -r1.5.10.1 -r1.5.10.2
--- openacs-4/packages/acs-templating/tcl/tab-procs.tcl	5 Oct 2013 12:55:10 -0000	1.5.10.1
+++ openacs-4/packages/acs-templating/tcl/tab-procs.tcl	16 Oct 2013 10:16:17 -0000	1.5.10.2
@@ -79,7 +79,7 @@
   set code [list template::form create $dlg_name]
  
   # Determine cookie name
-  if { [template::util::is_nil opts(cookie_name)] } {
+  if { ![info exists opts(cookie_name)] } {
     set cookie_name $dlg_name
   } else {
     set cookie_name $opts(cookie_name)
@@ -94,7 +94,7 @@
   upvar #$level $dlg_name:properties form_properties
 
   # Check parameters
-  if { ![template::util::is_nil opts(current_tab)] } {
+  if { [info exists opts(current_tab)] } {
     set current_tab $opts(current_tab)
   } else {
     # Check http
@@ -140,8 +140,8 @@
 
   # Set tab-specific params
 
-  if { [template::util::is_nil opts(base_url)] } {
-    if { ![template::util::is_nil properties(base_url)] } {
+  if { ![info exists opts(base_url)] } {
+    if { [info exists properties(base_url)] } {
       # use global base_url
       lappend code -base_url $properties(base_url)
     } else {
@@ -163,7 +163,7 @@
   upvar #$level $dlg_name:$name element
 
   # If this is the first tab being added, set it as current
-  if { [template::util::is_nil properties(current_tab)] } {
+  if { ![info exists properties(current_tab)] } {
     set_current_tab $dlg_name [lindex $properties(element_names) 0] 3
   }