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) {
		head2_over = newImage("images/nav/head2-over.gif");
		staff_over = newImage("images/nav/staff-over.gif");
		adv_over = newImage("images/nav/adv-over.gif");
		work_over = newImage("images/nav/work-over.gif");
		our_over = newImage("images/nav/our-over.gif");
		test_over = newImage("images/nav/test-over.gif");
		job_over = newImage("images/nav/job-over.gif");
		h_job_over = newImage("images/nav/h_job-over.gif");		
		h_staff_over = newImage("images/nav/h_staff-over.gif");
		h_adv_over = newImage("images/nav/h_adv-over.gif");		
		preloadFlag = true;
	}
}