var Slider = Class.create( {
	slider : null,
	currentThumb : null,

	initialize : function(slider) {
		this.slider = $(slider);
		this.currentThumb = $(slider).firstChild;
	},
	
	getCurrentThumb: function()
	{
		if(!this.currentThumb)
		{
			this.currentThumb = this.slider.firstChild;
		}
		
		return this.currentThumb;
	},
	
	reset: function()
	{
		this.slider.style.top = '0px';
		this.currentThumb = null;
	},

	moveDown : function(click) {
		if(this.getCurrentThumb()){
			if (nextThumb = this.getCurrentThumb().nextSibling) {
				this.moveTo(nextThumb, click);
			}
		}
	},

	moveUp : function(click) {
		if(this.getCurrentThumb()){
			if (previousThumb = this.getCurrentThumb().previousSibling) {
				this.moveTo(previousThumb, click);
			}
		}
	},

	moveTo : function(thumb, click) {
		if(this.getCurrentThumb()){
			var y = this.getCurrentThumb().offsetTop - thumb.offsetTop;
			new Effect.Move(this.slider, {
				y : y
			});
			
			if(click)
			{
				thumb.onclick();
			}
		}
		this.currentThumb = thumb;
	}
});