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) { 
		about_on = newImage("/img/head-mnu/about01o.jpg");
	    products_on = newImage("/img/head-mnu/products01o.jpg");
		manuf_on = newImage("/img/head-mnu/manuf01o.jpg");
		applic_on = newImage("/img/head-mnu/applic01o.jpg");		
		contacts_on = newImage("/img/head-mnu/contacts01o.jpg");		
		literat_on = newImage("/img/head-mnu/literat01o.jpg");
		quest_on = newImage("/img/head-mnu/quest01o.jpg");
		preloadFlag = true;
	}
}