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.getElementById(changeImages.arguments[i]).src = changeImages.arguments[i+1];
			//document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		index_over_07 = newImage("images/index_over_07.jpg");
		index_over_08 = newImage("images/index_over_08.jpg");
		index_over_09 = newImage("images/index_over_09.jpg");
		index_over_10 = newImage("images/index_over_10.jpg");
		index_over_11 = newImage("images/index_over_11.jpg");
		arrow_over = newImage("images/close_arrow.gif");
		
		preloadFlag = true;
	}
}