protected void gvMarca_Sorting(object sender, GridViewSortEventArgs e)
    {
        oMarcaBEList = (MarcaBEList)ViewState["oMarcaBEList"];
        SortDirection indOrden = (SortDirection)ViewState["ordenLista"];

        if (oMarcaBEList != null)
        {
            if (indOrden == SortDirection.Ascending)
            {
                oMarcaBEList.Ordenar(e.SortExpression, direccionOrden.Descending);
                ViewState["ordenLista"] = SortDirection.Descending;
            }
            else
            {
                oMarcaBEList.Ordenar(e.SortExpression, direccionOrden.Ascending);
                ViewState["ordenLista"] = SortDirection.Ascending;
            }
        }
        this.gvMarca.DataSource = oMarcaBEList;
        this.gvMarca.DataBind();
        ViewState["oMarcaBEList"] = oMarcaBEList;

        this.txhIdMarca.Value = String.Empty;
    }