var current_slide = 0;

function nextSlide() {
	if (current_slide < (ss_images.length - 1)) {	
		current_slide++;
	} else {
		current_slide = 0;
	}
	
	document.ss_image.src = ss_images[current_slide].src;
	document.ss_caption.src = ss_captions[current_slide].src;
}

function previousSlide() {
	if (current_slide > 0) {	
		current_slide--;
	} else {
		current_slide = (ss_images.length - 1);
	}
	
	document.ss_image.src = ss_images[current_slide].src;
	document.ss_caption.src = ss_captions[current_slide].src;
}