function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		nav1_on = newImage("images/en/nav/familyinvolvement-on.gif");
		nav1_off = newImage("images/en/nav/familyinvolvement-off.gif");
		nav2_on = newImage("images/en/nav/setgoals-on.gif");
		nav2_off = newImage("images/en/nav/setgoals-off.gif");
		nav3_on = newImage("images/en/nav/mealtimetips-on.gif");
		nav3_off = newImage("images/en/nav/mealtimetips-off.gif");
		nav4_on = newImage("images/en/nav/balanceddiet-on.gif");
		nav4_off = newImage("images/en/nav/balanceddiet-off.gif");
		nav5_on = newImage("images/en/nav/activity-on.gif");
		nav5_off = newImage("images/en/nav/activity-off.gif");
		nav6_on = newImage("images/en/nav/eatingouthealthy-on.gif");
		nav6_off = newImage("images/en/nav/eatingouthealthy-off.gif");
		nav7_on = newImage("images/en/nav/additionalresources-on.gif");
		nav7_off = newImage("images/en/nav/additionalresources-off.gif");
		
		preloadFlag = true;
	}
}