jQuery DataTable - select number of result

I use jQuery DataTable and I want call my function when I select number of results from dropdown. How can I do that?

DataTable generate code:

<div id="displayData_length" class="dataTables_length">
  <label>
     Show <select name="displayData_length" size="1" aria-controls="displayData">
             <option value="10" selected="selected">10</option>
             <option value="25">25</option>
             <option value="50">50</option>
             <option value="100">100</option>
           </select>
  </label>
</div>

So i try use function:

$('select[name=displayData_length]').bind('change', function(event) {
    alert($(this).val());
});

But it is not good, because I don't see alert() when I select number of result.

How can I do that? Maybe is another solution?