function visi(nr)
{
if (document.layers)
{
vista = (document.layers[nr].visibility == 'hide') ? 'show' : 'hide'
document.layers[nr].visibility = vista;
}
else if (document.all)
{
vista = (document.all[nr].style.visibility == 'hidden') ? 'visible'	: 'hidden';
document.all[nr].style.visibility = vista;
}
else if (document.getElementById)
{
vista = (document.getElementById(nr).style.visibility == 'hidden') ? 'visible' : 'hidden';
document.getElementById(nr).style.visibility = vista;
}
}