//Create array of nav bar "over" images
if (document.images) {
	
	camb_allston = new Image();
	camb_allston.src="images/camb_allston_nav_over.gif";
	lma = new Image();
	lma.src="images/lma_nav_over.gif";
	arsenal = new Image();
	arsenal.src="images/arsenal_nav_over.gif";
	arboretum = new Image();
	arboretum.src="images/arboretum_nav_over.gif";
	other = new Image();
	other.src="images/other_nav_over.gif";
	zoomOut = new Image();
	zoomOut.src="images/zoomOut_over.gif";
	pdflink = new Image();
	pdflink.src="images/pdflink_on.gif";
}
//Create array of nav bar "on" images
if (document.images) {
	camb_allstonon = new Image();
	camb_allstonon.src="images/camb_allston_nav_on.gif";
	lmaon = new Image();
	lmaon.src="images/lma_nav_on.gif";
	arsenalon = new Image();
	arsenalon.src="images/arsenal_nav_on.gif";
	arboretumon = new Image();
	arboretumon.src="images/arboretum_nav_on.gif";
	otheron = new Image();
	otheron.src="images/other_nav_on.gif";
	pdflinkon = new Image();
	pdflinkon.src="images/pdflink_on.gif";
	//zoomOuton = new Image();
	//zoomOuton.src="images/zoomOut_on.gif";
}

//Create array of nav bar "off" images
if (document.images) {
	camb_allstonoff = new Image();
	camb_allstonoff.src="images/camb_allston_nav.gif";
	lmaoff = new Image();
	lmaoff.src="images/lma_nav.gif";
	arsenaloff = new Image();
	arsenaloff.src="images/arsenal_nav.gif";
	arboretumoff = new Image();
	arboretumoff.src="images/arboretum_nav.gif";
	otheroff = new Image();
	otheroff.src="images/other_nav.gif";
	zoomOutoff = new Image();
	zoomOutoff.src="images/zoomOut.gif";
	pdflinkoff = new Image();
	pdflinkoff.src="images/pdflink.gif";
}

//function to activate images

function imgOn(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + ".src");
		
	}
}

//function to deactivate images

function imgOff(imgName,mapname) {
	if (document.images) {
		if (imgName == mapname) {
			document[imgName].src = eval(imgName + "on.src");}
		else {
		document[imgName].src = eval(imgName + "off.src");}
	}
}