protected void Page_Load(object sender, EventArgs e)
 {
     try
     {
         DAO_Entity daokh = new DAO_Entity();
         List <DTOPhieuDatVatLieuCC> dsdh = daokh.LayDSCongNoNCC();
         GridView1.DataSource = dsdh;
         GridView1.DataBind();
     }
     catch (Exception)
     {
         Response.Write("<script>alert('Loi tai du lieu!')</script>");
     }
 }