if (document.images) {
	img01up = new Image();
	img01up.src = "../img/top_ess.gif";
	img02up = new Image();
	img02up.src = "../img/b_home.gif";
	img03up = new Image();
	img03up.src = "../img/b_back.gif";
	img01dn = new Image();
	img01dn.src = "../img/top_ess2.gif";
	img02dn = new Image();
	img02dn.src = "../img/b_home2.gif";
	img03dn = new Image();
	img03dn.src = "../img/b_back2.gif";
}
// Function to 'activate'
function imgOn(imgName) {
	if (document.images) {
						            document[imgName].src = eval(imgName + "dn.src");
					}
	}
// Function to 'deactivate'
function imgOff(imgName) {
		if (document.images) {
				document[imgName].src = eval(imgName + "up.src");
		}
}
function essMouseOver(){
	imgOn('img01');
}
function essMouseOut(){
	imgOff('img01');
}

function homeMouseOver(){
	imgOn('img02');
}
function homeMouseOut(){
	imgOff('img02');
}
function backMouseOver(){
	imgOn('img03');
}
function backMouseOut(){
	imgOff('img03');
}