diff --git a/src/include/relation.h b/src/include/relation.h
index 3585c0771..7ef5f4038 100755
--- a/src/include/relation.h
+++ b/src/include/relation.h
@@ -383,11 +383,15 @@ public:
   const char* filter() const 
   { return _filter; }
   // @cmember Permette di mettere in attesa il cursore
-  void freeze(bool on = TRUE) 
+  void freeze(bool on = true) 
   { _frozen = on; }
+  void unfreeze() 
+  { _frozen = false; }
   // @cmember Controlla se il cursore e' congelato
   bool frozen() const 
   { return _frozen; }
+  bool not_frozen() const 
+  { return !_frozen; }
   // @cmember Permette di modificare l'espressione-filtro
   void setfilter(const char* filter_expr, bool update=FALSE, int limit = 0) 
   { _filter_update = update; _filter_limit = limit; filter(filter_expr); }