+
+static gboolean
+dialog_state_valid (gpointer data)
+{
+ struct sort_cases_dialog *scd = data;
+ GtkTreeModel *model = gtk_tree_view_get_model (scd->tv);
+
+ gint n_rows = gtk_tree_model_iter_n_children (model, NULL);
+
+ if ( n_rows == 0 )
+ return FALSE;
+
+ return TRUE;
+}
+