var delay = 3;
var first = true;
var rindex = 1;
var num = 4;

var rimg = new Array(num);

function rotateImage() {
	if (document.images && (preloadFlag == true)) {
		if (first == true) {
			first = false;
		} else {
			changeImages("rotate", rimg[rindex++%num].src);
		}
		setTimeout("rotateImage()", delay*1000);
	}
}

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) {
		rimg[0] = newImage("images/rotate/ross01916.jpg");
		rimg[1] = newImage("images/rotate/ross01926.jpg");
		rimg[2] = newImage("images/rotate/ross01957.jpg");
		rimg[3] = newImage("images/rotate/ross01964.jpg");
		preloadFlag = true;
	}
}