var current_slide = 0;
var slide_interval = 5000;
function reverseSlide()
	{
	jumpToSlide(current_slide-1);
	}
function advanceSlide()
	{
	jumpToSlide(current_slide+1);
	}
function jumpToSlide(slide)
	{
	clearInterval(slideshow);
	changeSlide(slide);
	slideshow = setInterval(advanceSlide, slide_interval);
	}
function changeSlide(slide)
	{
	if (slide == current_slide)
		return;

	var slides = document.getElementById('slides').getElementsByTagName('img');

	Effect.Fade('slide_'+current_slide);

	current_slide = slide;
	if (current_slide > slides.length-1)
		current_slide = 0;
	else if (current_slide < 0)
		current_slide = slides.length-1;

	Effect.Appear('slide_'+current_slide);
	}