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_abt_over = newImage("images/nav.abt-over.gif");
		nav_news_over = newImage("images/nav.news-over.gif");
		nav_de_serv_over = newImage("images/nav.de.serv-over.gif");
		nav_vir_hos_over = newImage("images/nav.vir.hos-over.gif");
		nav_re_hos_over = newImage("images/nav.re.hos-over.gif");
		nav_services_over = newImage("images/nav.services-over.gif");
		nav_supt_over = newImage("images/nav.supt-over.gif");
		nav_par_aff_over = newImage("images/nav.par.aff-over.gif");
		nav_contact_over = newImage("images/nav.contact-over.gif");
		preloadFlag = true;
	}
}