var image;
image_count = 3;
fade_timeout = 50;
rotate_interval = 3000;
var image_source;
opacity_percentage = 100;

if(window.addEventListener) window.addEventListener('load', function() {setTimeout(rotateImage, rotate_interval)}, false);
else if(window.attachEvent) window.attachEvent('onload', function() {setTimeout(rotateImage, rotate_interval)});

function rotateImage() {
	image = document.getElementById('homeTabRight').getElementsByTagName('img')[0];
	src = image.getAttribute('src');
	root = src.substr(0, src.length-5);
	index = src.substr(src.length-5, 1);
	index = parseInt(index, 10) + 1;
	if(index >= image_count) index = 0;
	extension = src.substr(src.length-4);
	image_source = root + index + extension;
	setTimeout(fadeOut, fade_timeout);
}

function getOpacity(percentage) {
	return((Math.sin((percentage - 50) / 100 * Math.PI) + 1) / 2);	
}

function fadeOut() {
	opacity_percentage -= 5;
	image.style.opacity = getOpacity(opacity_percentage);
	image.style.filter = 'alpha(opacity=' + (getOpacity(opacity_percentage) * 100) + ')';
	if(opacity_percentage > 0) setTimeout(fadeOut, fade_timeout);
	else {
		image.setAttribute('src', image_source);
		setTimeout(fadeIn, fade_timeout * 5);
	}
}

function fadeIn() {
	opacity_percentage += 5;
	image.style.opacity = getOpacity(opacity_percentage);
	image.style.filter = 'alpha(opacity=' + (getOpacity(opacity_percentage) * 100) + ')';
	if(opacity_percentage < 100) setTimeout(fadeIn, fade_timeout);
	else setTimeout(rotateImage, rotate_interval);
}