slides=["slide1", "slide2", "slide3"];
var pauseIncrement=0;
var slideIncrement=0;
var currentSlide=0;
var nextSlide=1;
var slideInterval=0; //This just initializes the setInterval so it can be called later
window.onload=setUp;

function setUp(){
	for (var i in slides){
		document.getElementById(slides[i]).style.left="1000px";
	}
	document.getElementById(slides[0]).style.left="0px"
	slideInterval=setInterval("pauseThenSlide()", 20);
}

function pauseThenSlide(){
	pauseIncrement++;
	if(pauseIncrement>=500){
		slide();
	}
}

function slide(){
	if(currentY(slides[currentSlide])<=-1000){
		pauseIncrement=0;
		document.getElementById(slides[currentSlide]).style.left=currentY(slides[currentSlide]) +2000 + "px";
		currentSlide++;
		if(currentSlide==slides.length){
			currentSlide=0;
		}
		nextSlide=(nextSlide==slides.length-1) ? 0 : currentSlide+1;
		return;
	}
	document.getElementById(slides[currentSlide]).style.left =currentY(slides[currentSlide]) -25 + "px";
	document.getElementById(slides[nextSlide]).style.left =currentY(slides[nextSlide]) -25 + "px";
}

function currentY(element){
	return document.getElementById(element).offsetLeft;
}