Index: openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml,v
diff -u -r1.50 -r1.50.2.1
--- openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml	30 Mar 2013 20:15:09 -0000	1.50
+++ openacs-4/packages/acs-core-docs/www/xml/developers-guide/tutorial-advanced.xml	27 Aug 2013 10:52:33 -0000	1.50.2.1
@@ -660,7 +660,7 @@
     			{submit:text(submit) {label "Set Mode"}}
 			} -on_submit {
     			parameter::set_value  -parameter "EnableCategoriesP" -value $enabled_p
-    			if {![empty_string_p $return_url]} {
+    			if {$return_url ne ""} {
         			ns_returnredirect $return_url
     			}
 			}
@@ -739,9 +739,9 @@
  	  # Site-Wide Categories
 		if { $use_categories_p == 1} {
     		set package_url [ad_conn package_url]
-    		if { ![empty_string_p $category_id] } {
+    		if { $category_id ne "" } {
         		set category_name [category::get_name $category_id]
-        		if { [empty_string_p $category_name] } {
+        		if { $category_name eq "" } {
             		ad_return_exception_page 404 "No such category" "Site-wide \
           			Category with ID $category_id doesn't exist"
             		return
@@ -1517,7 +1517,7 @@
     	{submit:text(submit) {label "Change"}}
 	} -on_submit {
     	parameter::set_value  -parameter "UseWysiwygP" -value $enabled_p
-    	if {![empty_string_p $return_url]} {
+    	if {$return_url ne ""} {
         	ns_returnredirect $return_url
     	}
 	}