jQuery cookie does not set in this script

I'm trying to extend this script to allow working with multiple pages.

Instead of using a single timestamp I want to use a comma-separated list like this: 1305536229613,1305536315210,1305536318026

The problem is the script server side sets cookies correctly but js code does not work (at least in Firefox 3.6.17 on Opensuse 11.3).

I had to add $.cookie(cookieName, null) (!) before setting time interval to get cookie = $.cookie(cookieName); to work 2 lines below... (how did I found it I don't know...).

Moreover updating the cookie does not work: I can see in another page using a server script cookie always growing

$(document).ready(function(){
    var cookieCheckTimer;
    var cookieName = 'download_token';
    var $wait = $('.wait');
    var $waitMsg = $('<span>Processing, please wait...</span>').prepend(
        $('<img />').attr('src', '/img/wait.gif').css({
            'vertical-align': 'middle',
            'margin-right': '1em'
        }));
    //add hidden field to forms with .wait submit
    $wait.parent().each(function(){
        $(this).append($('<input />').attr({
            'type': 'hidden',
            'name': cookieName,
            'id': cookieName
        }));
    });
    $wait.click(function(){
        var token = String(new Date().getTime());
        //set token value
        $('#' + cookieName).val(token);
        //hide submit buttons
        $(':submit').hide();
        //append wait msg
        $(this).after($waitMsg);
        //why?? don't know...
        $.cookie(cookieName, null) //<<<<<<<<<<
        //set interval
  开发者_Go百科      cookieCheckTimer = window.setInterval(function(){
            var cookie = $.cookie(cookieName);
            if (cookie != null){
                cookie = cookie.split(',');
                var idx = cookie.indexOf(token);
                if (idx >= 0){
                    //detach wait msg
                    $waitMsg.detach();
                    //show again submit buttons
                    $(':submit').show();
                    //remove token
                    cookie.splice(idx, 1);
                    //clear timer
                    window.clearInterval(cookieCheckTimer);
                    //update cookie value
                    if (cookie) $.cookie(cookieName, cookie.join(','));
                    else $.cookie(cookieName, null);
                }
            }
        }, 1000);
    });
});

I'm using latest version of the jquery.cookie plugin from repository