private void button17_Click(object sender, EventArgs e)
        {
            BindDataNhanVien();
            SMSRepostitory rep = new SMSRepostitory();
            WAITER_INFO dt = new WAITER_INFO();
            if (FormState == FormBase.FormStateType.New)
            {
                dt.NAME = textBox9.Text.Trim();
                dt.BIRTHDAY = dateTimePicker2.Value;
                dt.ADDRESS = textBox8.Text.Trim();
                dt.PHONE = textBox6.Text.Trim();


                rep.InsertWaiter(dt);
            }
            else if (FormState == FormBase.FormStateType.Edit)
            {
                dt.Id = PKEY;
                dt.NAME = textBox9.Text.Trim();
                dt.BIRTHDAY = dateTimePicker2.Value;
                dt.ADDRESS = textBox8.Text.Trim();
                dt.PHONE = textBox6.Text.Trim();
                rep.UpdateWaiter(dt);
            }
            FormState = FormBase.FormStateType.Normal;
           LoadDataNhanVien();
        }