Index: openacs-4/packages/categories/tcl/category-form-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/categories/tcl/category-form-procs.tcl,v
diff -u -r1.1 -r1.2
--- openacs-4/packages/categories/tcl/category-form-procs.tcl	6 Feb 2004 17:22:25 -0000	1.1
+++ openacs-4/packages/categories/tcl/category-form-procs.tcl	24 Mar 2004 10:39:58 -0000	1.2
@@ -61,7 +61,11 @@
 	util_unlist $tree tree_id name subtree_id assign_single_p require_category_p
         upvar #[template::adp_level] \
           __category__ad_form__$element_name\_${tree_id} my_category_ids
-        eval lappend category_ids $my_category_ids
+        if {[info exists my_category_ids]} { 
+            eval lappend category_ids $my_category_ids
+        } else { 
+            ns_log Warning "category::ad_form::get_categories: __category__ad_form__$element_name\_${tree_id} for tree $tree_id not found"
+        }
     }
     return $category_ids
 }