var do_slides = true;
var list_items = null;
var ul_height = 0;

function slideshow() {
	list_items = document.getElementById('slideshow').getElementsByTagName('li');
	if (document.getElementById && document.getElementsByTagName) {
		for (i=0;i<list_items.length;i++) {
			list_items[i].className = 'slide_off';
		}
		document.getElementById('slideshow').className = 'slideshow_active';
		ul_height = document.getElementById('slideshow').offsetHeight;
		emptyNode('slideshow_info');
		document.getElementById('slideshow_info').appendChild(document.createTextNode('Slide 1 of ' + list_items.length));
		next_slide();
	}
}

function emptyNode(node_id) {
	if (document.getElementById(node_id)) {
		var node_list = document.getElementById(node_id).childNodes ;
		if (node_list.length > 0 ) {
			for (i=0;node_list.length>0;i++) {
				document.getElementById(node_id).removeChild(node_list[0]);
			}
		}
	}
}

function next_slide() {
	if (document.getElementById('lightbox') && document.getElementById('lightbox').style.display != 'none') {
		// don't go to next slideshow if lightbox image showing
		setTimeout('next_slide();',4000);
		return true;
	}
	var this_slide = (-1);
	for (i=0;i<list_items.length;i++) {
		if (list_items[i].className == 'slide_on') {
			list_items[i].className = 'slide_off';
			this_slide = i;
		}
	}
	this_slide += 1;
	if (this_slide >= list_items.length || this_slide < 0) {
		this_slide = 0;
	}
	list_items[this_slide].className = 'slide_on';
	var li_height = list_items[this_slide].offsetHeight;
	// look for image in case there's one floating that's bigger than the basic li height
	var li_imgs = list_items[this_slide].getElementsByTagName('img');
	for (i=0;i<li_imgs.length;i++) {
		if (li_imgs[i].offsetHeight > li_height) {
			li_height = li_imgs[i].offsetHeight;
		}
	}
	if (li_height > (ul_height - 10)) {
		ul_height = (li_height + 10);
		document.getElementById('slideshow').style.height = (ul_height + 'px');
	}
	list_items[this_slide].style.marginTop = (parseInt((ul_height - li_height) / 2) + 'px');
	document.getElementById('slideshow_info').childNodes[0].data = ('Slide ' + (this_slide + 1) + ' of ' + list_items.length);
	if (do_slides) setTimeout('next_slide();',4000);
}



// copied from Lightbox

function slideshow_addLoadEvent(func)
{	
	var oldonload = window.onload;
	if (typeof window.onload != 'function'){
    	window.onload = func;
	} else {
		window.onload = function(){
		oldonload();
		func();
		}
	}

}

slideshow_addLoadEvent(slideshow);