设置cookie、获取cookie和删除cookie

简化在JavaScript中创建，读取和删除cookie

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使用以下三个功能处理Cookie。

function getCookie(name) {
    var v = document.cookie.match('(^|;) ?' + name + '=([^;]*)(;|$)');
    return v ? v[2] : null;
}

function setCookie(name, value, days) {
  var d = new Date;
  d.setTime(d.getTime() + 24 * 60 * 60 * 1000 * days);
  document.cookie = name + "=" + value + ";path=/;expires=" + d.toGMTString();
}

function deleteCookie(name) { setCookie(name, '', -1); }