var visibile = null;
var hidden = null;
var layered = false;
var byID = false;
var all = false;
	
if(document.layers)
{
	visible = 'show';
	hidden = 'hide';
	layered = true;
}
else if(document.getElementById)
{
	visible = 'visible';
	hidden = 'hidden';
	byID = true;
}
else
{
	visible = 'visible';
	hidden = 'hidden';
	all = true;
}