//requires jquery

function slide(div_id) {
	$div = $('#' + div_id)[0];
	$img_el = $('#' + div_id + ' img');
	
	var img_back = $img_el.get(0);
	var img_front = $img_el.get(1);

	data = $.data($div, 'data');
	$.data($div, 'next', data.files[data.count % data.files.length]);

	if (img_front.style.display == 'none') {
		$(img_front).fadeIn(data['switch'] * 1000);
		$(img_back).fadeOut(data['switch'] * 1000);
		setTimeout(function() { img_back.src = $.data($('#' + div_id)[0], 'next'); }, data['switch'] * 1000);
	} else {
		$(img_front).fadeOut(data['switch'] * 1000);
		$(img_back).fadeIn(data['switch'] * 1000);
		setTimeout(function() { img_front.src = $.data($('#' + div_id)[0], 'next'); }, data['switch'] * 1000);
	}
	data['count']++;
}