"First" jQuery Plugin - Any critic / advice?

Hi,
I ended up last week with a really ugly piece of non reusable code where I basically wanted to open a modal, passing some data to it, and return data back when the modal close.
After some research I realized it's time to figure out how to create a jQuery plugin (something I always steered clear from, why I don't know)

Anyhow, here's some code I got working that I will be using in my "real" app at work and figured I post it here asking for some critic, tips and advice.
If anyone have a sec, have a look and let me know (I know it's annoying when someone post a lot of code...)

[Edit] just before posting I realized each subsequent time I open the modal, the callback function get called one more time. Ooops...something about bind/unbind no?

Code:

---

<div class="well">
    <h3>Simple Modal using Plugin</h3>
    <div>
        Simply open a modal using a strongly typed partial view, but this time we use a jQuery Plugin that can be re-used  (I hope)
    </div>
    <div>
        Title:
        <input type="text" id="txtTitle" placeholder="enter a title" />
    </div>
    <div>
        Url:
        <input type="text" id="txtUrl" placeholder="enter a url" />
    </div>
    <input type="hidden" id="modalReturnData"/>
    <a href="#" id="showModal">Open Modal</a>
</div>

<!-- ***** Modal ***** -->
<div id="myModal" class="modal hide fade">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal">&times;</button>
        <h3 id="modalTitle"></h3>
    </div>
    <div class="modal-body" id="modalContent">
    </div>
    <div class="modal-footer">
        <a href="#" class="btn" data-dismiss="modal" >Close</a>
    </div>
</div>
<!-- ***** End Modal ***** -->

@section ViewScripts {
    <script type="text/javascript">

        $(document).ready(function () {
            $('#showModal').click(function () {
                $('#myModal').bootstrapModal(
                    {
                        title: $('#txtTitle').val(),
                        url: $('#txtUrl').val()
                    },
                    function (data) {
                        $('#modalReturnData').val(data.join(","));
                        alert($('#modalReturnData').val());
                    }
                );
            });
        });
        // todo:  put in separate file...
        (function($) {
            $.fn.extend({
                bootstrapModal: function(options, callback) {
                    var defaults = {
                        title: "default title",
                        url: "default url"
                    };
                    options = $.extend(defaults, options);
                    return this.each(function() {
                        $('#modalTitle', this).text(options["title"]);
                        $('#modalContent', this).text(options["url"]);
                        $(this).modal('show');

                        $(this).bind('hidden', function() {
                            if (typeof callback == 'function') {
                                // just some DEMO DATA, for instance will be id's of all selected checkboxes
                                var demoIds = new Array();
                                for (var i = 0; i < 5; i++) {
                                    demoIds.push(i);
                                }
                                callback.call(this, demoIds);
                            }
                        });
                    });
                }
            });
        })(jQuery);
    </script>
}

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