var perPage = 3;
var currentSlide = 1;
function slideNext(object, count, scrollable, type, dontChangeClass) {
	var width;
	// if count is < perPage (1 || 2)
	(count < perPage) ? width = 0 : width = (count-perPage) * 220;
	//width = (count-perPage) * 220;
	var leftDisp = -parseInt($(scrollable).getStyle('left'));

	if(leftDisp < width) {
		var num = object.id.split('_');
		var disp = parseInt(num[1]) * -220;
		$(scrollable).setStyle({left: disp+'px'});
		var newId = parseInt(num[1]) + 1;
		object.id = num[0]+'_'+newId;
		currentSlide = newId;
		// prev
		var prev = parseInt(num[1]) - 1;
		if(!dontChangeClass) {
			addClass('prev', type+'prev_'+prev)
			removeClass('disabled-left', type+'prev_'+prev)
		}
		$(type+'prev_'+prev).id = type+'prev_'+parseInt(prev + 1);
		// disable
		if (-parseInt($(scrollable).getStyle('left')) == width) {
			if(!dontChangeClass) {
				removeClass('next', object.id);
				addClass('disabled-right', object.id)
			}
		}
	}
}

function slidFirst(scrollable, type) {
	$(scrollable).setStyle({left: 0});
	prevSlide = currentSlide - 1;
	nextSlide = currentSlide;

	$(type+'prev_'+prevSlide).id = type+'prev_0';
	$(type+'next_'+nextSlide).id = type+'next_1';
	currentSlide = 1
}

function slidePrevious(object, count, scrollable, type, dontChangeClass) {
	var num = object.id.split('_');
	var newId = parseInt(num[1]) - 1;

	if(newId >= 0) {
		left = parseInt($(scrollable).getStyle('left'))
		disp = left + 220;
		// scroll carousel to the left by 220px
		$(scrollable).setStyle({left: disp+"px"});
		// set prev new id
		object.id = num[0]+'_'+newId;
		// enable next
		var next = parseInt(num[1]) + 1;
		if(!dontChangeClass) {
			addClass('next', type+'next_'+next);
			removeClass('disabled-right', type+'next_'+next);
		}
		// set next new id
		$(type+'next_'+next).id = type+'next_'+parseInt(num[1]);
		currentSlide = parseInt(num[1]);
		// disable prev
		if (parseInt($(scrollable).getStyle('left')) == 0) {
			if(!dontChangeClass) {
				addClass('disabled-left', object.id);
				removeClass('prev', object.id);
			}
		}
	}
}

function addClass(className, id) {
	if($(id)) {
		$(id).addClassName(className);
	}
}

function removeClass(className, id) {
	if($(id)) {
		$(id).removeClassName(className);
	}
}