Pass array of checkboxes?

Hi,

I'm trying to develop a simple plugin.

When the user clicks the icon for the plugin, they will be show a list of checkboxes. These checkboxes are generated via an SJAX request and the number created will vary:

var folders = new Array();

         var request = $.ajax({
           url: '/folders',
           type: "GET",
           dataType: "json",
           async: false
         });

         request.done(function(data) {
            $.each(data, function(i,item){
     
               folders[i] = {
                        'type' : 'checkbox',
                        'id' : 'folders['+i+']',
                        'label' : item.title
               }
               
             });
         });

I then pass this folders array to the contents of a tab in the dialog box.

How can I group these checkboxes together and find out which ones have been checked in the onOk function?

When I try and get the value of 'folders', it just returns true:

onOk : function() {
    var dialog = this;
    alert(dialog.getValueOf( 'tab1', 'folders'));
}

Any advice appreciated.

Thanks.