private void PostPageChanges()
        {
            ToDoListNavigator toDoListNavigator = new ToDoListNavigator(toDoListNavigatorTDS);

            // Update toDoListNavigator rows
            foreach (GridViewRow row in grdToDoListNavigator.Rows)
            {
                string toDoIdLabel = ((Label)row.FindControl("lblToDoId")).Text.Trim();
                int toDoId = Int32.Parse(toDoIdLabel.ToString().Trim());
                bool selected = ((CheckBox)row.FindControl("cbxSelected")).Checked;

                toDoListNavigator.Update(toDoId, selected);
            }

            toDoListNavigator.Data.AcceptChanges();

            // Store datasets
            Session["toDoListNavigatorTDS"] = toDoListNavigatorTDS;
        }