/*
example $.cookie(’name’, ‘value’);
设置cookie的值，把name变量的值设为value
example $.cookie(’name’, ‘value’, {expires: 7, path: ‘/’, domain: ‘jquery.com’, secure: true});
新建一个cookie 包括有效期 路径 域名等
example $.cookie(’name’, ‘value’);
新建cookie
example $.cookie(’name’, null);
删除一个cookie

var account= $.cookie('name');
取一个cookie(name)值给myvar

*/


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(); // use expires attribute, max-age is not supported by IE
   }
   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 { // only name given, get cookie
   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]);
   // Does this cookie string begin with the name we want?
   if (cookie.substring(0, name.length + 1) == (name + '=')) {
   cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
   break;
   }
   }
   }
   return cookieValue;
   }
};