jQuery.cookie = function(name, value, options) {
  if (typeof value != 'undefined') { // name and value given, set cookie
    options = options || {};
    if (value === null) {
      value = '';
      options.expires = -1;
    }
    var expires = '';
    if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) {
      var date;
      if (typeof options.expires == 'number') {
        date = new Date();
        date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000));
      } else {
        date = options.expires;
      }
      expires = '; expires=' + date.toUTCString();
    }
    var path = options.path ? '; path=' + (options.path) : '';
    var domain = options.domain ? '; domain=' + (options.domain) : '';
    var secure = options.secure ? '; secure': '';
    document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');
  } else {
    var cookieValue = null;
    if (document.cookie && document.cookie != '') {
      var cookies = document.cookie.split(';');
      for (var i = 0; i < cookies.length; i++) {
        var cookie = jQuery.trim(cookies[i]);
        if (cookie.substring(0, name.length + 1) == (name + '=')) {
          cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
          break;
        }
      }
    }
    return cookieValue;
  }
};

//使用方法如下:
//設置cookie的鍵值對
//$.cookie('name', ‘value');
//設置cookie的鍵值對，有效期，路徑，域，安全
//$.cookie('name', ‘value', {expires: 7, path: ‘/', domain: ‘jquery.com', secure: true});
//新建一個cookie 包括有效期 路徑 域名等
//讀取cookie的值
//var account= $.cookie('name');
//刪除一個cookie
//example $.cookie('name', null);