private void TraineeForm_Load(object sender, EventArgs e)
        {
            idSelector.Items.Clear();
            tn = new Trainee();
            var lst = tn.IDList();

            foreach (var ls in lst)
            {
                idSelector.Items.Add(ls.ToString());
            }
            if (lst.Count != 0)
            {
                tn.GetDetail(lst[0]);
                FillData(tn);
                this.idSelector.SelectedIndex = 0;
            }
            else
            {
                MessageBox.Show("No Trainee Record Available", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
                this.Close();
            }
        }
 private void idSelector_SelectedIndexChanged(object sender, EventArgs e)
 {
     tn = new Trainee();
     tn.GetDetail(int.Parse(idSelector.SelectedItem.ToString()));
     FillData(tn);
 }