private void buttCreaAlb_Click(object sender, RoutedEventArgs e) { if (checkOp("Crea")) { CreaAlberoWindow creaAlberoWindow = new CreaAlberoWindow(treeHandler, attrDef, client); creaAlberoWindow.ShowDialog(); } else { ParametersErrorWindow err = new ParametersErrorWindow(false, "Errore lato server.."); err.ShowDialog(); } }