function primaryNavOn(a)
{
	var td = a.parentNode;
	
	td.className = "on";
	
	td.leftRule = getAdjacentElement(td, td.nodeType, "previous");
	td.rightRule = getAdjacentElement(td, td.nodeType, "next");
	
	if ((td.leftRule) && (td.leftRule.className == "rule"))
	{
		td.leftRule.className = "rule-on";
	}
	else
	{
		td.leftRule = null;
	}

	if ((td.rightRule) && (td.rightRule.className == "rule"))
	{
		td.rightRule.className = "rule-on";		
	}	
	else
	{
		td.rightRule = null;
	}
}

function primaryNavOff(a)
{
	var td = a.parentNode;
	
	td.className = "";

	if (td.leftRule)
	{
		td.leftRule.className = "rule";
	}
	if (td.rightRule)
	{
		td.rightRule.className = "rule";
	}	
}

function tertiaryNavOn(a)
{
	var td = a.parentNode;
	
	td.className = "on";
}

function tertiaryNavOff(a)
{
	var td = a.parentNode;
	
	td.className = "off";
}

function getAdjacentElement(el, nt, str)
{
	var sib = eval("el." + str + "Sibling");
	
	if (sib)
	{
		if (sib.nodeType != nt)
		{
			return getAdjacentElement(sib, nt, str);
		}
	}
	
	return sib;
}