function addCookie(objName,objValue,objHours)
{//添加cookie
var str = objName + "=" + escape(objValue);
if(objHours > 0)
{
//为0时不设定过期时间，浏览器关闭时cookie自动消失
var date = new Date();
var ms = objHours*3600*1000;
date.setTime(date.getTime() + ms);
str += "; expires=" + date.toGMTString();
}
document.cookie = str;
}

function getCookie(objName)
{
//获取指定名称的cookie的值
var arrStr = document.cookie.split("; ");
for(var i = 0;i < arrStr.length;i ++)
{
var temp = arrStr[i].split("=");
if(temp[0] == objName) return unescape(temp[1]);
}
}

function delCookie(name){
//为了删除指定名称的cookie，可以将其过期时间设定为一个过去的时间
var date = new Date();
date.setTime(date.getTime() - 10000);
document.cookie = name + "=a; expires=" + date.toGMTString();
}

function delAllCookie(){
var date = new Date();
date.setTime(date.getTime() - 10000);
var arrStr = document.cookie.split("; ");
for(var i = 0;i < arrStr.length;i ++)
{
   var temp = arrStr[i].split("=");
   document.cookie = temp[0] + "=a; expires=" + date.toGMTString();

 }
}

function allCookie(){
//读取所有保存的cookie字符串
var str = document.cookie;
if(str == ""){
str = "没有保存任何cookie";
}
alert(str);
}
function chkCookie()
{
var str = document.cookie;
if(str=="")
{return false;}
else
{
var arrStr =str.split("; ");
var temp = arrStr[0].split("=");
if(temp[0]=="rtime") return false;
else return true; 

}
}