JQuery操作cookies

 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
         }
         // CAUTION: Needed to parenthesize options.path and options.domain
         // in the following expressions, otherwise they evaluate to undefined
         // in the packed version for some reason...
         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;
     }
 };