var state = 'none';

            function showhide(layer_ref) {

            if (state == 'block') {
            state = 'none';
            }
            else {
            state = 'block';
            }
            if (document.all) { //IS IE 4 or 5 (or 6 beta)
            eval( "document.all." + layer_ref + ".style.visibility = state");            }
            if (document.layers) { //IS NETSCAPE 4 or below
            document.layers[layer_ref].display = state;
            }
            if (document.getElementById && !document.all) {
            maxwell_smart = document.getElementById(layer_ref);
            maxwell_smart.style.display = state;
            }
            }