function layout() {
                h = document.getElementById('body').scrollHeight ;
                document.getElementById( 'page' ).style.height = h ;
                var panel = document.getElementById( 'panel' ) ;
                panel.style.height = h ;

                var ph = panel.style.height
                document.getElementById( 'panel_r' ).style.height = ph ;
                document.getElementById( 'panel_l' ).style.height = ph ;
        }