function visible(zone)
{
	if (document.layers)
	{
		document.layers[zone].visibility = 'show';
	}
	else if (document.all)
	{
		document.all[zone].style.visibility = 'visible';
	}
	else if (document.getElementById)
	{
		document.getElementById(zone).style.visibility = 'visible';

	}
}
function invisible(zone)
{
	if (document.layers)
	{
		document.layers[zone].visibility = 'hide';
	}
	else if (document.all)
	{
		document.all[zone].style.visibility = 'hidden';
	}
	else if (document.getElementById)
	{
		document.getElementById(zone).style.visibility = 'hidden';
	}
}

function blocking(nr)
{
	if (document.layers)
	{
		document.layers[nr].display = 'block';
	}
	else if (document.all)
	{
		document.all[nr].style.display = 'block';
	}
	else if (document.getElementById)
	{
		document.getElementById(nr).style.display = 'block';
	}
}
function unblocking(nr)
{
	if (document.layers)
	{
		document.layers[nr].display = 'none';
	}
	else if (document.all)
	{
		document.all[nr].style.display = 'none';
	}
	else if (document.getElementById)
	{
		document.getElementById(nr).style.display = 'none';
	}
}