if (document.images) {
	
	homeon = new Image(); 
	homeon.src = "images/navigation/home_on.gif";

	homeoff = new Image();
	homeoff.src = "images/navigation/home_off.gif";
	
	serviceson = new Image(); 
	serviceson.src = "images/navigation/services_on.gif";

	servicesoff = new Image();
	servicesoff.src = "images/navigation/services_off.gif";
	
	contacton = new Image(); 
	contacton.src = "images/navigation/contact_on.gif";

	contactoff = new Image();
	contactoff.src = "images/navigation/contact_off.gif";

	}

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

	function turnOff(imageName) {
		if (document.images) {
		  document[imageName].src = eval(imageName + "off.src");

	}
	}