问在Bootstrap模态上调用两次以上的回调函数

EN

<a href="#" class="confirm_delete">test modal</a>

<div class="modal fade" id="general_modal" tabindex="-1" role="dialog" aria-labelledby="general_modalLabel" aria-hidden="true">
<div class="modal-dialog">
    <div class="modal-content">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
             <h4 class="modal-title" id="general_modal_title">Set Title Here</h4>

        </div>
        <div class="modal-body">set modal content here</div>
        <div class="modal-footer">
            <button type="button" class="btn btn-default close_button" data-dismiss="modal">Close</button>
            <button type="button" class="btn btn-primary action_button">Save changes</button>
        </div>
    </div>
</div>

(function ($) {
$.fn.showDialog = function (options, callback) {
    $('#general_modal').modal();
    $('#general_modal .action_button').on('click', function () {
        callback();
    });
}
}(jQuery));

$('.confirm_delete').click(function (e) {
    e.preventDefault();
    $(this).showDialog(null, function () {
        alert('xxx');
    });

});