var alertScroller = new Class({
	
	//implements
	Implements: [Options],

	//options
	options: {
		container: 'alertContainer',
		nav: 'alertNavigation',
		list: 'alertList',
		currentNum: 0,
		offsetY:0,
		delayTime:5000
	},
	
	//initialization
	initialize: function(options) {
		//set options
		this.setOptions(options);
		if($chk($(this.options.container)) == false){return false;}
		this.container = $(this.options.container);
		this.list = $(this.options.list);
		this.list.setStyle('top',this.options.currentNum * $pick(this.options.rotateHeight,this.container.getHeight()) + this.options.offsetY)
		this.tweener = new Fx.Tween(this.list);
		this.btnNext = $(this.options.nav).getElement('.next')
		this.btnPrevious = $(this.options.nav).getElement('.previous')
		this.btnNext.addEvent('click',function(){$clear(this.periodical); this.scrollUp()}.bind(this))
		this.btnPrevious.addEvent('click',function(){$clear(this.periodical); this.scrollDown()}.bind(this))
		this.periodical = this.scrollUp.periodical(5000,this);
	},
	
	scrollUp: function() {
		if(this.list.getStyle('top').toInt() + this.list.getHeight() - $pick(this.options.rotateHeight,this.container.getHeight()) > 1  + this.options.offsetY){
			this.tweener.start('top',this.list.getStyle('top').toInt() - $pick(this.options.rotateHeight,this.container.getHeight()))
		}else{
			this.tweener.start('top',0)
		}
	},
	scrollDown: function() {
		if(this.list.getStyle('top').toInt() < 0  - this.options.offsetY){
			this.tweener.start('top',this.list.getStyle('top').toInt() + $pick(this.options.rotateHeight,this.container.getHeight()))
		}else{
			this.tweener.start('top',0 - this.list.getHeight() + $pick(this.options.rotateHeight,this.container.getHeight()))
		}
	}
	
});