function setCookie(name,value,domainName,existDays)
{
    var exp  = new Date();    //new Date("December 31, 9998");
    exp.setTime(exp.getTime() + existDays*24*60*60*1000);
    document.cookie = name + "="+ escape (value) + ";domain="+domainName+";expires=" + exp.toGMTString();
}

//读取cookies函数
function getCookie(name)
{
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
    if(arr != null) return unescape(arr[2]); return null;
}

//删除cookie  
function delCookie(name,domainName,path) {
    var exp = new Date();
    exp.setTime(exp.getTime() - 100000);
    var cval=getCookie(name);
    if(cval!=null) {document.cookie= name + "="+cval+";domain="+domainName+";path="+path+";expires="+exp.toGMTString();}
}

//获取子cookie值，采用：fur:blue/food:biscuits/name:Cookie_Monster方式来分隔
function getSubCookie(cookieName, subCookieName)
{
    var cookieValue=getCookie(cookieName);
    var subCookies = cookieValue.split("/");
    for (var j = 0; j < subCookies.length; j++)
    {
        var subCookieCrumbs = subCookies[j].split(":");
        if (subCookieCrumbs[0] == subCookieName)
        {
            return subCookieCrumbs[1];
        }
    }
}