diff --git a/include/mask.cpp b/include/mask.cpp
index 623d414c3..0fdd30842 100755
--- a/include/mask.cpp
+++ b/include/mask.cpp
@@ -872,17 +872,24 @@ long TMask::handler(WINDOW w, EVENT* ep)
       case WC_NOTEBK:
         if (ep->v.ctl.ci.win == _notebook)
         {
+          const bool changing = ep->v.ctl.ci.v.notebk.page == NULL_WIN;
 					const int new_page = ep->v.ctl.ci.v.notebk.page_new;
-					if (new_page != _page && new_page < _pages) // Cambio pagina effettivo
-					{
-            bool can_proceed = true;
-            if (_focus >= 0 && find_parent_page(fld(_focus)) != new_page)
-              can_proceed = check_current_field();
-            if (can_proceed)
-							show_page(new_page);
-            else
-              return 1;
-					}
+					if (changing) // Tentativo di cambio pagina
+          {
+            if (new_page != _page && new_page < _pages) 
+					  {
+              if (_focus >= 0 && find_parent_page(fld(_focus)) != new_page)
+              {
+                if (!check_current_field())
+                  return 1;
+              }
+					  }
+          }
+          else
+          {
+            // Cambio pagina avvenuto
+            show_page(new_page); // Forza il focus al primo campo
+          }
         }
         break;
       case WC_ICON:                             // In realta' trattasi di bottone di toolbar