var showOverlay = null;
var preloadFlag = false;


function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}


function changeNavImages() 
	{
	resetNav();
	if (showOverlay == changeNavImages.arguments[0])
		{
		showOverlay = null;
		} else {
		showSubnavOverlay(changeNavImages.arguments[0]);
		if (document.images && (preloadFlag == true)) 
			{
			for (var i=0; i<changeNavImages.arguments.length; i+=2) 
				{
				document[changeNavImages.arguments[i]].src = changeNavImages.arguments[i+1];
				}
			}
		}
	}
////
function showSubnavOverlay(id)
	{
	showOverlay = id;
	divID = 'div_' + id + '_sub';
	document.getElementById(divID).style.display = 'block';
	}
function resetNav()
	{
	hideNavOverlays();
	im = document.getElementsByTagName('img');
	for(i=0;i<im.length;i++)
		{
		if (im[i].id.substr(0,'t2_mh_'.length) == 't2_mh_')
			{
			key = im[i].id.substr('t2_mh_'.length);
			a = key.split('_');
			key = a[0];
			name = im[i].id.substr(0, (im[i].id.length-3));
			im.src = imNavArr[a[0]];
			document[name].src =  imNavArr[a[0]];
			}
		}
	}
function hideNavOverlays()
	{
	d = document.getElementsByTagName('div');
	for(i=0;i<d.length;i++)
		{
		if (d[i].id.substr(0,'div_t2_mh'.length) == 'div_t2_mh')
			{
			d[i].style.display = 'none';
			}
		}
	}