protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { drLop.DataSource = gvDAL.GetLop(); drLop.DataTextField = "TenLop"; drLop.DataValueField = "MaLop"; DataBind(); ddlmonhoc.DataSource = gvDAL.GetMonHoc(); ddlmonhoc.DataTextField = "TenMonHoc"; ddlmonhoc.DataValueField = "MaMonHoc"; DataBind(); } }