var nImage = 1;
var MAX_IMAGE = 3;
var nImgIndex = -1;

function initialize() {
	window.setInterval("changeimage()", 15000);
}

function changeimage() {
	nImage++;

	if (nImage > MAX_IMAGE) {
		nImage = 1;
	}

	showimage(nImage);
}

function showimage(index) {
	var sImage;
	
	var nValue = 0;

	if (nImgIndex == -1) {
		for (i=1; i<=((document.images.length)-1); i++) {
			if ((document.images[i].width == 480) && (document.images[i].height == 150)) {
				nImgIndex = i;
				break;
			}
		}
	}

	sImage = 'http://www.wahana.com/images/splash' + index + '.jpg';

	document.images[nImgIndex].src = sImage;
}

initialize();