I'm trying to save the toggle state of collapsable boxes using cookies. Here's my code:

HTML:

<div class="box_container">
    <div class="box_handle">
        Title
    </div>
    <div class="box" data-title="admin_actions">
        Content
    </div>
</div>

Javascript:

$('div.box_container div.box_handle').click(function() {
    $(this).next('.box').slideToggle('fast');
});
$.each($('div.box_container div.box_handle'), function(index,value){
    if ($.cookie('show_box_' + $(value).next('.box').attr('data-title')) != 'closed'){
        $(value).next('.box[data-title="' + $('.box').attr('data-title') + '"]').hide();
    }
});
var new_value = "";
window.onbeforeunload = function() {
    $.each($('div.box_container div.box_handle'),function(index,value){
        new_value = ($(value).next('.box').css('display') == 'none') ? 'open' : 'closed';
        $.cookie('show_box_' + $(value).next('.box').attr('data-title'), new_value);
    });
}

Now, my problem is:

Any boxes other than the first one will always appear opened. It does set a cookie for it, but does not hide it if cookie is set to closed Only for each first box on a page it works. How can I fix this?