// 建立 cookie
function setCookie(name, value, expires, path, domain, secure) {
   var cookieText = encodeURIComponent(name) + '=' + encodeURIComponent(value);
   if (expires instanceof Date) {
       cookieText += '; expires=' + expires;
   }

   if (path) {
       cookieText += '; expires=' + expires;
   }

   if (domain) {
       cookieText += '; domain=' + domain;
   }

   if (secure) {
       cookieText += '; secure';
   }

   document.cookie = cookieText;
}
// 獲取 cookie
function getCookie(name) {
   var cookieName = encodeURIComponent(name) + '=';
   var cookieStart = document.cookie.indexOf(cookieName);
   var cookieValue = null;
   if (cookieStart > -1) {
       var cookieEnd = document.cookie.indexOf(';', cookieStart);
       if (cookieEnd == -1) {
           cookieEnd = document.cookie.length;
       }
       cookieValue = decodeURIComponent(document.cookie.substring(cookieStart +
       cookieName.length, cookieEnd));
    }
   return cookieValue;
}
// 刪除 cookie
function unsetCookie(name) {
   document.cookie = name + "= ; expires=" + new Date(0);
}