protected void Button2_Click(object sender, EventArgs e)
        {
            string macongty    = Session["congty"].ToString();
            string maloaiphieu = DropDownLoaiPhieu.SelectedValue.ToString();

            if (DropDownLoaiPhieu.SelectedValue.ToString() == " ")
            {
                if (DropDownLDonVi.SelectedValue.ToString() == " ")
                {
                    GridView1.DataSource = db.LayDanhSachQuyTrinhXetDuyetCuaCanBo(macongty);
                    GridView1.DataBind();
                }
                else
                {
                    if (DropDownLDonVi.SelectedValue.ToString().Trim() != "")
                    {
                        string madonvi = DropDownLDonVi.SelectedValue.ToString();
                        //GridView1.DataSource = QuyTrinhXetDuyetCuaCanBoDAO.LayDanhSachQuyTrinhTheoBoPhan(madonvi, macongty);
                        GridView1.DataSource = db.LayQuyTrinhTheoDonViCanBo(madonvi, macongty);
                        GridView1.DataBind();
                    }
                }
            }
            else
            {
                if (DropDownLDonVi.SelectedValue.ToString() == " ")
                {
                    GridView1.DataSource = db.LayQuyTrinhTheoLoaiPhieuCanBo(maloaiphieu, macongty);
                    GridView1.DataBind();
                }
                else
                {
                    string madonvi = DropDownLDonVi.SelectedValue.ToString();
                    GridView1.DataSource = db.LayQuyTrinhTheoDonViCanBoVaLoaiPhieu(madonvi, macongty, maloaiphieu);
                    GridView1.DataBind();
                }
            }
        }