// slideShowSpeed includes time it takes to fade
// so with:
// var slideShowSpeed = 5000;
// var crossFadeDuration = 1000;
//
//	each slide will show for 4 seconds without the fade effect
//

var slideShowSpeed = 5000;
var crossFadeDuration = 1000;

//don't change anything below here
var timeout = 13;
var delta = timeout / crossFadeDuration;

var container;
var imgs;

var index = 0;

function init() {
	container = document.getElementById('slideshow');
	if (!container)
		return false;

	var nl = container.getElementsByTagName('img');

	imgs = Array(nl.length);
	for (var i = 0; i < nl.length; i++)
		imgs[i] = nl[i];
	
	container.style.position = "relative";

	reorderImages();
	setTimeout('runSlideShow()', slideShowSpeed);
}

function runSlideShow() {
	
	if (imgs.length < 2)
		return;

	if (document.all)
		IEtransition();
	else
		transition();

	setTimeout('runSlideShow()', slideShowSpeed);
}

function reorderImages(shift)
{
	if (shift)
	{
		var imgtop = imgs.shift();
		imgs.push(imgtop);
	}

	for (var i = 0; i < imgs.length; i++)
	{
		imgs[i].style.zIndex = imgs.length - i;
		imgs[i].style.position = "absolute";
	}
}

var tid = null;
function transition()
{
	if (tid)
	{
		if (imgs[0].style.opacity <= 0.0)
		{
			clearTimeout(tid);
			tid = null;
			reorderImages(true);
			return;
		}

		imgs[0].style.opacity -= delta;
	}
	else
	{
		imgs[0].style.opacity = 1.0;
		imgs[1].style.opacity = 1.0;
	}

	tid = setTimeout('transition()', timeout);
}


var opacity = 1.0;
function IEtransition(container)
{
	if (tid)
	{
		if (opacity <= 0.0)
		{
			clearTimeout(tid);
			tid = null;
			opacity = 1.0;
			reorderImages(true);
			return;
		}

		opacity -= delta;
		imgs[0].style.filter = 'alpha(opacity=' + opacity * 100 + ')';
	}
	else
	{
		imgs[0].style.filter = "alpha(opacity=100)";
		imgs[1].style.filter = "alpha(opacity=100)";
	}

	tid = setTimeout('IEtransition()', timeout);
}

window.onload = function () {
	init();
};