ImageSlide = {
	_display_div: "ImageSlide_div",
	_img_selected: 0,
	_img_div: "slide_img_",
	_pos: 0,
	_show: 3,
	_move_dist: 67,
	
	_timer: "",
	_loop_counter: 0,
	_loop_dist: 0,
	
	next: function(){
		if(this.isNext()){
			this._img_selected+=3;
			this.move();
		}
	},
	
	prev: function(){
		if(this.isPrev()){
			this._img_selected-=3;
			this.move();
		}
	},
	
	move: function(){
		if(document.getElementById(ImageSlide._display_div)){
			var target_pos = (-ImageSlide._move_dist*ImageSlide._img_selected);
			var dist = ImageSlide._pos-target_pos;
			this._loop_counter = 8;
			this._loop_dist = dist / this._loop_counter;
			this.run_move();
			this.display_arrows();
		}
	},
	
	run_move: function(){
		ImageSlide._pos -= ImageSlide._loop_dist;
		document.getElementById(ImageSlide._display_div).style.left = ImageSlide._pos+"px";
		ImageSlide._loop_counter--;
		if(ImageSlide._loop_counter>0)
			ImageSlide._timer = window.setTimeout(function(){ImageSlide.run_move()},20);
		else{
			window.clearTimeout(ImageSlide._timer);
			ImageSlide.initPos();	
		}
	},
	
	initPos: function(){
		ImageSlide._pos = (-ImageSlide._move_dist*ImageSlide._img_selected);
		document.getElementById(ImageSlide._display_div).style.left = ImageSlide._pos+"px";
	},
	
	gotoPos: function(pos){
		pos -= this._max-1;
		if(pos < 0)
			pos = 0;
		this._botton = pos;
		this.move();
	},
	
	display_arrows: function(){
		document.getElementById("offer_link_1").style.visibility = (this.isNext())? "visible" : "hidden";		
		document.getElementById("offer_link_0").style.visibility = (this.isPrev())? "visible" : "hidden";
	},
	
	isNext: function(){		
		var last = this._show + this._img_selected;
		return document.getElementById(this._img_div+last);
	},
	
	isPrev: function(){		
		var first = this._img_selected - 1;
		return document.getElementById(this._img_div+first);
	}
}