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) {
		h01 = newImage("/research/images/navi_artists.gif");
		h02 = newImage("/research/images/navi_home.gif");
		h03 = newImage("/research/images/navi_outline.gif");
		h04 = newImage("/research/images/navi_calendar.gif");
		hb01 = newImage("/research/images/navi_navi_b_artists.gif");
		hb02 = newImage("/research/images/navi_b_home.gif");
		hb03 = newImage("/research/images/navi_b_outline.gif");
		hb04 = newImage("/research/images/navi_b_calendar.gif");
		preloadFlag = true;
	}
}