function MostrarCapa(capa) {
    if (document.getElementById && document.getElementById(capa) != null)
        document.getElementById(capa).style.visibility='visible';
    else if (document.layers && document.layers[capa] != null)
        document.layers[capa].visibility = 'show';
    else if (document.all)
        document.all[capa].style.visibility = 'visible';
}

function OcultarCapa(capa) {
    if (document.getElementById && document.getElementById(capa) != null)
        document.getElementById(capa).style.visibility='hidden';
    else if (document.layers && document.layers[capa] != null)
        document.layers[capa].visibility = 'hide';
    else if (document.all)
        document.all[capa].style.visibility = 'hidden';
}