window.addEvent('domready', function() {
var slides = $$('#slides_container img');
var show = true;
	slides.each(function(item, index){
		item.setStyles({
			opacity:0,
			'z-index':index
		});
	});
	slides[0].setStyle('opacity',1);
function runSlides(newPhoto){
		//find slide with opacity greater than 0
		slides.each(function(slide, index){
			if(slide.getStyle('opacity')>0) {
				slide.tween('opacity',0);
				if(show == true){
					if(index < slides.length-1){
					newPhoto = index + 1;
					} else {
					newPhoto = 0;
					}
				}
			}
		});
		slides[newPhoto].tween('opacity',1);
		slide_buttons.setStyle('background-color','726658');
		slide_buttons[newPhoto].setStyle('background-color','958C82');
	}
//run slideshow
var timer = runSlides.periodical(3000);

//set up buttons
var slide_buttons = $$('.photo_id');
	slide_buttons.each(function(btn, index){
		btn.addEvent('click', function(){
			show = false;
   			 clearInterval(timer);
			runSlides(index);
		});
	});
});