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) {
		navi_01_over = newImage("images/navi_01-over.gif");
		navi_02_navi_01_over = newImage("images/navi_02-navi_01_over.gif");
		navi_03_navi_01_over = newImage("images/navi_03-navi_01_over.gif");
		navi_04_navi_01_over = newImage("images/navi_04-navi_01_over.gif");
		navi_05_navi_01_over = newImage("images/navi_05-navi_01_over.gif");
		navi_06_navi_01_over = newImage("images/navi_06-navi_01_over.gif");
		navi_07_navi_01_over = newImage("images/navi_07-navi_01_over.gif");
		navi_08_navi_01_over = newImage("images/navi_08-navi_01_over.gif");
		navi_09_navi_01_over = newImage("images/navi_09-navi_01_over.gif");
		navi_10_navi_01_over = newImage("images/navi_10-navi_01_over.gif");
		preloadFlag = true;
	}
}