private void btnAdd_Click(object sender, EventArgs e)
        {
            AddManager a = new AddManager(null);

            a.Visible = true;
            //this.Visible = false;
        }
        private void btnEdit_Click(object sender, EventArgs e)
        {
            if (managerdetailsBindingSource.Current == null)
            {
                return;
            }

            using (AddManager am = new AddManager(managerdetailsBindingSource.Current as Manager_details))
            {
                if (am.ShowDialog() == DialogResult.OK)
                {
                    managerdetailsBindingSource.DataSource = cmd.Manager_details.ToList();
                }
            }
        }