/*
Revised javascript for navigation bars
27/07/02 SF
*/

var m_sCurrentLayer = "";

function ShowHideNavLayers(sNewLayer)
{
	var sRootLayer = m_sCurrentLayer.substring(0, m_sCurrentLayer.indexOf('_') + 2);
	
	// hide the current layer, but not if the new layer is a child of the old
	if(m_sCurrentLayer != "" && sNewLayer.indexOf(m_sCurrentLayer) == -1)
	{
		o = GetElement(m_sCurrentLayer);
		if (o.getAttribute('nav') != 'stayopen')
		{
			o.style.display = 'none';
		}
	}
	// if the new layer is not a child of the root, hide the root layer
	if(m_sCurrentLayer != "" && sNewLayer.indexOf(sRootLayer) == -1)
	{
		o = GetElement(sRootLayer);
		if (o.getAttribute('nav') != 'stayopen')
		{
			o.style.display = 'none';
		}
	}
	
	// show the new layer
	o = GetElement(sNewLayer);
	if (o.getAttribute('nav') != 'stayopen')
	{
		o.style.display = (o.style.display == 'none') ? '' : 'none';
	}

	// set the current layer	
	m_sCurrentLayer = sNewLayer;
}

var m_bIE4 = (document.all && !document.getElementById);
function GetElement(sLayerId)
{
	return (m_bIE4) ? document.all(sLayerId) : document.getElementById(sLayerId);
}