void loadUnit()
 {
     DonViTinhDAO d = new DonViTinhDAO();
     drUnit.DataSource = d.SelectAll();
     drUnit.DataTextField = "TenDonVi";
     drUnit.DataValueField = "ID_DonViTinh";
     drUnit.DataBind();
 }
        protected void repeaterChild_OnItemDataBound(object sender, RepeaterItemEventArgs e)
        {
            if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
            {
                DropDownList ddlMenhGia = (DropDownList)e.Item.FindControl("ddlMenhGia");
                MenhGiaDAO mgdao = new MenhGiaDAO();
                ddlMenhGia.DataSource = mgdao.DanhSach();
                ddlMenhGia.DataTextField = "MenhGia";
                ddlMenhGia.DataValueField= "ID_MenhGia";
                //ddlMenhGia.SelectedValue = ((HiddenField)e.Item.FindControl("ID_MenhGia")).ToString();
                ddlMenhGia.DataBind();

                DropDownList ddlDonVi = (DropDownList)e.Item.FindControl("ddlDonVi");
                DonViTinhDAO dvtinhDao = new DonViTinhDAO();
                ddlDonVi.DataSource = dvtinhDao.SelectAll();
                ddlDonVi.DataTextField = "TenDonVi";
                ddlDonVi.DataValueField = "ID_DonViTinh";
                //ddlDonVi.SelectedValue = ((HiddenField)e.Item.FindControl("ID_DonViTinh")).ToString();
                ddlDonVi.DataBind();
            }
        }