cookie的使用以及cookie的跨域名获取

 //设置COOKIEs
    function setCOOKIE(name, value) {
        var Days = 30;
        var exp = new Date();
        exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
        document.COOKIE = name + "=" + value + ";expires=" + exp.toGMTString()";
    }

    //读取COOKIEs
    function getCOOKIE(name) {
        var arr,
            reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
        if (arr = document.COOKIE.match(reg)) {
            return arr[2];
        }
        else {
            return null;
        }

    }

    //删除COOKIEs
    function delCOOKIE(name) {
        var exp = new Date();
        exp.setTime(exp.getTime() - 1);
        var cval = getCOOKIE(name);
        if (cval != null)
            document.COOKIE = name + "=" + cval + ";expires=" + exp.toGMTString();
    }
//使用举例
setCOOKIE("REG_GUID","This is set COOKIE!");
getCOOKIE("REG_GUID");

//设置COOKIE，使之能跨域获取
    function setCOOKIE(name, value) {
        var Days = 30;
        var exp = new Date();
        exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
        document.COOKIE = name + "=" + value + ";expires=" + exp.toGMTString() + "; path=/" + ";domain=.baidu.com";
    }