if (document.images) {

//rollovers
		home = new Image();
		home_down = new Image();
		about = new Image();
		about_down = new Image();
		service = new Image();
		service_down = new Image();
		principle = new Image();
		principle_down = new Image();
		contact = new Image();
		contact_down = new Image();
		whypic = new Image();
		whypic_down = new Image();

		home.src = "images/home.gif";
		home_down.src = "images/home_on.gif";
		about.src = "images/about.gif";
		about_down.src = "images/about_on.gif";
		service.src = "images/service.gif";
		service_down.src = "images/service_on.gif";
		principle.src = "images/principle.gif";
		principle_down.src = "images/principle_on.gif";
		contact.src = "images/contact.gif";
		contact_down.src = "images/contact_on.gif";
		whypic.src = "images/whypic.gif";
		whypic_down.src = "images/whypic_on.gif";

}

function buttonOn(imageName) {
	if (document.images) {
		document[imageName].src = eval(imageName+"_down.src")
		}
	}

function buttonOff(imageName) {
	if (document.images) {
		document[imageName].src = eval(imageName+".src")
		}
	}