function aprire(m)
{
    if (document.all)
    {
        document.all(m).style.visibility = "Visible";
    }
    else
    {
        document.layers(m).style.visibility = "Show";
    }
}
function chiudere(m)
{
    if (document.all)
    {
        document.all(m).style.visibility = "Hidden";
    }
    else
    {
        document.layers(m).style.visibility = "Hide";
    }
}