private void cboitemcategory_SelectedIndexChanged(object sender, EventArgs e) { if (cboitemcategory.Text != "" && cboitemcategory.Text != "Choose One" && cboitemcategory.SelectedIndex != 0) { DataTable dt = blod.get_item_by_cateogory_id(Convert.ToInt32((cboitemcategory.SelectedValue))); if (dt.Rows.Count > 0) { DataRow dr = dt.NewRow(); dr["item_name"] = "Choose One"; dt.Rows.InsertAt(dr, 0); cbo_item_name.DataSource = dt; cbo_item_name.DisplayMember = "item_name"; cbo_item_name.ValueMember = "item_id"; } } }