private void btnCreateDemoCompetition_Click(object sender, EventArgs e) { DEMO_COMPETION cNew = new DEMO_COMPETION(); cNew.demoCompID = Convert.ToInt32(txtDemoTestID.Text); cNew.subtractID = cbMHDemo.SelectedValue.ToString(); cNew.expDate = dtExp.Value; cNew.gradeid = Convert.ToInt32(cbDemoKhoi.SelectedValue); cNew.iddemotest = Convert.ToInt32(cbDemoDe.SelectedValue); TracNghiem.ThemKyThiThu(cNew); OnLoad(e); }