function product(data){
	var self = this;
	this.data = data;
	var imageCount = this.data.length>6?6:this.data.length;
	var $ = function(o){
		if(typeof o == "object"){
			return o;
		} else if(typeof o == "string") {
			return document.getElementById(o);
		}
		return document.getElementById(o.toString());
	}
	
	var viewImages = new Array(imageCount);
	var getFirstImageIndex = function(){
		var image = viewImages[0];
		if(image){
			var id = image.value;
			for(var i=0,l=self.data.length;i<l;i++){
				if(id == self.data[i].id){
					return i;
				}
			}
			return -1;
		}
	}
	var getLastImageIndex = function(){
		var image = viewImages[imageCount-1];
		if(image){
			var id = image.value;
			for(var i=0,l=self.data.length;i<l;i++){
				if(id == self.data[i].id){
					return i;
				}
			}
			return -1;
		}
	}
	var setForwardAndBack = function(){
		if(isMoveLeft()){
			setHasForward();
		} else {
			setNotHasForward();
		}
		if(isMoveRight()){
			setHasBack();
		} else {
			setNotHasBack();
		}
	}
	var move = function(step){
		var index = getFirstImageIndex();
		if(step<0){
			if(isMoveLeft()){
				loadImages(self.data.slice(index+step,imageCount+index+step));
			} 
			
		} else if (step>0) {
			if(isMoveRight()){
				loadImages(self.data.slice(index+step,imageCount+index+step));

			} 
		}
	}
	this.moveLeft = function(){
		move(-1);
	}
	this.moveRight = function(){
		move(1);
	}
	this.selected = function(image){
		//设置小图的选中class
		setImageSelected(image);
		//设置前一次选中图片的class
		if(selectedImageId!==image.id){
			clearSelectedImage();	
		}
		selectedImageId = image.id;
		//设置大图的变化		
		$("bimage").src = image.bimage;
		//此处可以修改图片的链接地址
		//$("bigimage").href = image.orimage;
	    //显示图片描述信息//////////////////////////////////////////////////////////////////////
		document.getElementById("title").innerHTML=image.desc;	
	    //alert(info.name);
	}
	this.display = function(){
		loadImages(self.data.slice(0,imageCount));
	}
	var createImage = function(info){
		try{
			var image = document.createElement("IMG");
			//image.id = "simage"+info.id;
			image.id = info.id;
			image.src = info.simage;
			image.value = info.id;
			image.bimage = info.bimage;
			image.desc = info.desc;
			image.selected = false;
			

			
			image.onclick = function(){
				if(this.id!=selectedImageId){
					self.selected(this);
				}
			}
			image.onmouseover = function(){
				if(this.id!=selectedImageId){
					setImageLight(this);
				}
			}
			image.onmouseout = function(){
				if(this.id!=selectedImageId){
					setImageNormal(this);
				}
			}
			return image;
		} finally{
			image = null;
		}
	}
	var isMoveLeft = function(){
		var index = getFirstImageIndex();
		if(index<=0){
			return false;
		}
		return true;
	}
	var isMoveRight = function(){
		var index = getLastImageIndex();
		if(index>=self.data.length-1){
			return false;
		}
		return true;
	}
	var selectedImageId = -1;
	var loadImages = function(infos){  
		if(!infos||infos.length==0) return;
		for(var i=0;i<infos.length;i++){
			var info = infos[i];
			if(!info) continue;
			var image = createImage(info);
			
			if(image){
				if(typeof viewImages[i]!="undefined"){
					$("p"+i).replaceChild(image,viewImages[i]);
				} else {
					$("p"+i).appendChild(image);
				}
				if(image.id!==selectedImageId){
					setImageNormal(image);
					
				} else {
					setImageSelected(image);
				}
				//080822加入默认状态，liujunfei
				if(i==0){
					self.selected(image);
				}				
				viewImages[i] = image;
			}
		}
		setForwardAndBack();
	}
	var getSelectedImage = function(){
		var id = selectedImageId;
		for(var i=0,l=self.data.length;i<l;i++){
			var image = self.data[i];
			if(image&&image.id===id){
				return image;
			}
		}
		return null;
	}
	var setCls = function(ele,cls){
		$(ele).className = cls;
	}
	var setHasForward = function(){
		setCls("forward","pre-has");
	}
	var setNotHasForward =  function(){
		setCls("forward","pre-none");
	}
	var setHasBack = function(){
		setCls("back","next-has");
	}
	var setNotHasBack =  function(){
		setCls("back","next-none");
	}
	var setImageNormal = function(ele){
		setCls($(ele).parentNode.parentNode.parentNode,"");
	}
	var setImageSelected = function(ele){
		setCls($(ele).parentNode.parentNode.parentNode,"prd-img-cur");
	}
	var setImageLight = function(ele){
		setCls($(ele).parentNode.parentNode.parentNode,"prd-img-mos");
	}
	var clearSelectedImage = function(){
		if(selectedImageId>=0){
			if($(selectedImageId)){
				setImageNormal($(selectedImageId));
			}
		}
	}
}