File Upload AJAX

jQuery(function($){

   $(document).bind('gform_post_render', function(event, form_id){

    if (form_id == 1) {
        var uploader = $("#gform_drag_drop_area_1_1");
        var uploads = $("#gform_uploaded_files_1").val();

        uploader.on("drop", function() {

        $.ajax({
        url: mp3_object.ajaxurl,
        async: true,
            type: "POST",
            data: {
        action : 'ajax_mp3',
        files : uploads,
            },

            success: function(response) {
                alert(response);
            }
            });

        });


        }
    });
});