+ /**
+ * create a menubar based on a PropertyList within the PropertyTree
+ */
+ void make_menubar (SGPropertyNode * props);
+
+
+ /**
+ * destroy a menubar based on a PropertyList within the PropertyTree
+ */
+ void destroy_menubar ();
+
+
+ /**
+ * Disable/enable menu titles and entries
+ */
+ bool enable_item (const SGPropertyNode * item, bool state);
+
+