private void btnApprove_Click(object sender, RoutedEventArgs e)
        {
            List <Entry> entries = new List <Entry>();

            for (int i = 0; i < dgHours.SelectedItems.Count; i++)
            {
                entries.Add((Entry)dgHours.SelectedItems[i]);
            }
            queries.Approval_Approve(entries, user);
            RefreshDGHoursFromClassList();
        }