Dim strPagina As String = String.Format("gruppi_lavoro_dett.aspx?COD_GLAV={0}", "NUOVO")
        Dim popupScript As String = "<script language='javascript'>window.showModalDialog('" & strPagina & "', 'CustomPopUp', " & _
                            "'width=500, height=300, menubar=no, resizable=yes')</script>"

        Page.RegisterStartupScript("PopupScript", popupScript)