js中自定义cookie操作

function setCookie(c_name, value, expiredays) {
    var exdate = new Date()
    exdate.setDate(exdate.getDate() + expiredays)
    document.cookie = c_name + "=" + escape(value)
            + ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString())
}

function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) {
                c_end = document.cookie.length;
            }
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}

function clearCookie(c_name) {
    setCookie(c_name, "", -1);
}

参考资料 http://www.w3school.com.cn/