if (document.images) {
	
	var homeOn = new Image()
	homeOn.src = "nav/home_on.gif"
	var homeOff = new Image()
	homeOff.src = "nav/home.gif"
	
	var aboutOn = new Image()
	aboutOn.src = "nav/about_on.gif"
	var aboutOff = new Image()
	aboutOff.src = "nav/about.gif"

	var currentOn = new Image()
	currentOn.src = "nav/current_on.gif"
	var currentOff = new Image()
	currentOff.src = "nav/current.gif"
	
	var sponsorsOn = new Image()
	sponsorsOn.src = "nav/sponsors_on.gif"
	var sponsorsOff = new Image()
	sponsorsOff.src = "nav/sponsors.gif"
	
	var researchOn = new Image()
	researchOn.src = "nav/previous_on.gif"
	var researchOff = new Image()
	researchOff.src = "nav/previous.gif"
	
	var careersOn = new Image()
	careersOn.src = "nav/careers_on.gif"
	var careersOff = new Image()
	careersOff.src = "nav/careers.gif"
	
	var directionsOn = new Image()
	directionsOn.src = "nav/map_on.gif"
	var directionsOff = new Image()
	directionsOff.src = "nav/map.gif"
	
	var contactOn = new Image()
	contactOn.src = "nav/contact_on.gif"
	var contactOff = new Image()
	contactOff.src = "nav/contact.gif"
	
	var phase1On = new Image()
	phase1On.src = "nav/phase1_on.gif"
	var phase1Off = new Image()
	phase1Off.src = "nav/phase1.gif"
	
}

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

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