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) {
		home_over = newImage("images/home-over.jpg");
		personnel_over = newImage("images/personnel-over.jpg");
		company_over = newImage("images/company-over.jpg");
		products_over = newImage("images/products-over.jpg");
		lasers_over = newImage("images/lasers-over.jpg");
		optics_over = newImage("images/optics-over.jpg");
		opto_mechanics_over = newImage("images/opto_mechanics-over.jpg");
		instruments_over = newImage("images/instruments-over.jpg");
		suppliers_over = newImage("images/suppliers-over.jpg");
		contact_over = newImage("images/contact-over.jpg");
		circle_laser_over = newImage("images/circle_laser-over.jpg");
		circle_optics_over = newImage("images/circle_optics-over.jpg");
		circle_optomechanics_over = newImage("images/circle_optomechanics-over.jpg");
		circle_instruments_over = newImage("images/circle_instruments-over.jpg");
		preloadFlag = true;
	}
}