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

function addCookie(objName,objValue,objHours,objDomain,objPath)
{//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();
    }
    if(objDomain!="")
    {
        str += "; domain=" + objDomain;
    }
    if(objPath!="")
    {
        str += "; path=" + objPath;
    }
    document.cookie = str;
}

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 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";
    }
    return str;
}