//设置全局变量，减少变量
var GLOBAL={}
GLOBAL.namespace=function(str){
var arr=str.split("."),o=GLOBAL;
for(i=(arr[0]=="GLOBAL")?1:0;i<arr.length;i++){
o[arr[i]]=o[arr[i]]||{};
o=o[arr[i]];
}
}

//封装cookie
GLOBAL.namespace("Cookie");
GLOBAL.Cookie={
//读取
read:function(name){
var cookieStr=";"+document.cookie+";";
var index=cookieStr.indexOf(";"+name+"=");
if(index!=-1){
var s=cookieStr.substring(index+name.length+3,cookieStr.length);
return unescape(s.substring(0,s.indexOf(";")));
}else{
return null;
}
};
//设置
set:function(name,value,expires){
var exDays=expires*24*60*60*1000;
var expDate=new Date();
expDate.setTime(expDate.getTime()+expDays);
var expString=expires?";expires="+expDate.toGMTString():"";
var pathString=";path=/";
document.cookie=name+"="+escape(value)+expString+pathString;
};
//删除
del:function(name){
var exp=new Date(new Date().getTime()-1);
var s=this.read(name);
if(s!=null){
document.cookie=name+"="+s+";expires"+exp.toGMTString()+;"path=/";
}
}
}

使用命名空间封装cookie