$('.breadcrumb').after('<div class="alert alert-success">' + json['success'] + '<button type="button" class="close" data-dismiss="alert">×</button></div>');
<div id="myModal" class="modal fade bs-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel">
<div class="modal-dialog modal-sm">
<div class="modal-content">
</div>
</div>
</div>
$('#myModal').find('.modal-content').html(json['success']);
$('#myModal').modal('show');