var aboutOn = new Image(); aboutOn.src = "/images/nav/about-on.gif";
var aboutOff = new Image(); aboutOff.src = "/images/nav/about.gif";

var portfolioOn = new Image(); portfolioOn.src = "/images/nav/portfolio-on.gif";
var portfolioOff = new Image(); portfolioOff.src = "/images/nav/portfolio.gif";

var contactOn = new Image(); contactOn.src = "/images/nav/contact-on.gif";
var contactOff = new Image(); contactOff.src = "/images/nav/contact.gif";

var blogOn = new Image(); blogOn.src = "/images/nav/blog-on.gif";
var blogOff = new Image(); blogOff.src = "/images/nav/blog.gif";

function imgOn(imageName) {
	document[imageName].src = eval(imageName + "On.src");
}
function imgOff(imageName) {
	document[imageName].src = eval(imageName + "Off.src");
}