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) {
		nav_home_over = newImage("image/nav-home-over.gif");
		nav_visitor_over = newImage("image/nav-visitor-over.gif");
		nav_whatwedo_over = newImage("image/nav-whatwedo-over.gif");
		nav_resources_over = newImage("image/nav-resources-over.gif");
		nav_events_over = newImage("image/nav-events-over.gif");
		nav_classes_over = newImage("image/nav-classes-over.gif");
		nav_support_over = newImage("image/nav-support-over.gif");
		nav_shop_over = newImage("image/nav-shop-over.gif");
		nav_enews_over = newImage("image/nav-enews-over.gif");
		nav_contact_over = newImage("image/nav-contact-over.gif");
		nav_bioblitz_2 = newImage("image/nav-bioblitz_2.gif");
		support_main_01_7 = newImage("image/support_main_01_7.gif");
		support_main_milestones_8 = newImage("image/support_main_milestones_8.gif");
		support_main_contributions_9 = newImage("image/support_main_contributio-09.gif");
		preloadFlag = true;
	}
}