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) {
		res_perf_07_over = newImage("images/res_perf_07-over.gif");
		res_perf_10_over = newImage("images/res_perf_10-over.gif");
		res_perf_12_over = newImage("images/res_perf_12-over.gif");
		res_perf_17_over = newImage("images/res_perf_17-over.gif");
		res_perf_19_over = newImage("images/res_perf_19-over.gif");
		res_perf_21_over = newImage("images/res_perf_21-over.gif");
		res_perf_23_over = newImage("images/res_perf_23-over.gif");
		res_perf_25_over = newImage("images/res_perf_25-over.gif");
		res_perf_27_over = newImage("images/res_perf_27-over.gif");
		res_perf_29_over = newImage("images/res_perf_29-over.gif");
		one_over = newImage("images/image_1.gif");
		two_over = newImage("images/image_2.gif");
		three_over = newImage("images/image_3.gif");
		four_over = newImage("images/image_4.gif");
		five_over = newImage("images/image_5.gif");
		preloadFlag = true;
	}
}