ns4 = (document.layers)? true:false ie4 = (document.all)? true:false function muestra(id) { alert("muestra") if (ns4){ document.layers[id].visibility = "show"; } else { document.all[id].style.visibility = "visible"; } } function oculta(id) { alert("oculta") if (ns4){ document.layers[id].visibility = "hide"; } else{ document.all[id].style.visibility = "hidden"; } }