var addHistory=function(num,id){
  stringCookie=getCookie('history');
  var stringHistory=""!=stringCookie?stringCookie:"{history:[]}";
  var json=new JSON(stringHistory);
  var e="{num:"+num+",id:"+id+"}";
  json['history'].push(e);//添加一個新的記錄
  setCookie('history',json.toString(),30);
}
//顯示歷史記錄
var DisplayHistory=function(){
  var p_ele=document.getElementById('history');
   while (p_ele.firstChild) {
   p_ele.removeChild(p_ele.firstChild);
   }
  var historyJSON=getCookie('history');
  var json=new JSON(historyJSON);
  var displayNum=6;
  for(i=json['history'].length-1;i>0;i--){
    addLi(json['history'][i]['num'],json['history'][i]['id'],"history"); 
    displayNum--;
    if(displayNum==0){break;}
  }
}
//添加一個li元素
var addLi=function(num,id,pid){
  var a=document.createElement('a');
  var href='product.action?pid='+id;
  a.setAttribute('href',href);
  var t=document.createTextNode(num);
  a.appendChild(t);
  var li=document.createElement('li');
  li.appendChild(a);
  document.getElementById(pid).appendChild(li);
}
//添加cookie
var setCookie=function(c_name,value,expiredays)
{
  var exdate=new Date()
  exdate.setDate(exdate.getDate()+expiredays)
  cookieVal=c_name+ "=" +escape(value)+((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
//  alert(cookieVal);
  document.cookie=cookieVal;
}
//獲取cookie
function getCookie(c_name)
{
  if (document.cookie.length>0)
   {
   c_start=document.cookie.indexOf(c_name + "=")
   if (c_start!=-1)
    {
    c_start=c_start + c_name.length+1
    c_end=document.cookie.indexOf(";",c_start)
    if (c_end==-1) c_end=document.cookie.length
//    document.write(document.cookie.substring(c_start,c_end)+"<br>");
    return unescape(document.cookie.substring(c_start,c_end))
    }
   }
  return ""
}

var JSON = function(sJSON){
  this.objType = (typeof sJSON);
  this.self = [];
  (function(s,o){for(var i in o){o.hasOwnProperty(i)&&(s[i]=o[i],s.self[i]=o[i])};})(this,(this.objType=='string')?eval('0,'+sJSON):sJSON);
}
JSON.prototype = {
  toString:function(){
    return this.getString();
  },
  valueOf:function(){
    return this.getString();
  },
  getString:function(){
    var sA = [];
    (function(o){
      var oo = null;
      sA.push('{');
      for(var i in o){
        if(o.hasOwnProperty(i) && i!='prototype'){
          oo = o[i];
          if(oo instanceof Array){
            sA.push(i+':[');
            for(var b in oo){
              if(oo.hasOwnProperty(b) && b!='prototype'){
                sA.push(oo[b]+',');
                if(typeof oo[b]=='object') arguments.callee(oo[b]);
              }
            }
            sA.push('],');
            continue;
          }else{
            sA.push(i+':'+oo+',');
          }
          if(typeof oo=='object') arguments.callee(oo);
        }
      }
      sA.push('},');
    })(this.self);
    return sA.slice(0).join('').replace(/
objectobject
,/ig,'').replace(/,\}/g,'}').replace(/,\]/g,']').slice(0,-1);
  },
  push:function(sName,sValue){
    this.self[sName] = sValue;
    this[sName] = sValue;
  }
}