Twitter Bootstrap: dropdown

HTML

<link rel="stylesheet" href="http://getbootstrap.com/2.3.2/assets/css/bootstrap.css">
<link rel="stylesheet" href="http://getbootstrap.com/2.3.2/assets/css/bootstrap-responsive.css">
<script src="http://getbootstrap.com/2.3.2/assets/js/bootstrap.js"></script>
<div class="dropdown">

</div>
<div class="btn-group"> <a class="btn btn-sm" href="#" style="width:200px;text-align:right;background-color:white;border-color:lightgray">choose an action</a>
 <a class="btn btn-primary dropdown-toggle" data-toggle="dropdown" href="#"><span class="caret"></span></a>

    <ul class="dropdown-menu">
        <li><a href="#">
	<input type="checkbox" class="dropdown_item" value='30' checked><font color="blue">Edit</font>
</a>
        </li>
        <li><a href="#"><input type="checkbox" class="dropdown_item" value='40'> Delete</a>
        </li>
        <li><a href="#"><input type="checkbox" class="dropdown_item" value='40'> Ban</a>
        </li>
        <li class="divider"></li>
        <li><a href="#"><input type="checkbox" class="dropdown_toggle_all"><font color="olive">Select All/Clear All</font></a>
        </li>
    </ul>
</div>
</div>
<button>
aaa</button>
</button>

JavaScript

$('.dropdown_item').on('click', function(event){
	//event.preventDefault();
  event.stopPropagation();
})

$('.dropdown_toggle_all').click(function(){
  event.stopPropagation();
  $(this).closest('.dropdown-menu').find('.dropdown_item').prop('checked',$(this).prop('checked'));
  var container = $(this).closest('.dropdown-menu');
  // Take the checked boxes and gather em up
  var labels = [];
  var values = [];

  container.find('input[type=checkbox].dropdown_item:checked').each(function(item){

    labels.push($(this).closest('a').text().trim());
    values.push($(this).val());
  });

  // Now set the UI
  if( values.length > 200 ){
    container.find('.dropdown-toggle').html(labels.length+' selected');
  }else if( values.length > 0 ){
    container.find('.dropdown-toggle').html(labels.join(', '));
  }else{
    container.find('.dropdown-toggle').html(container.data('default-label'));
  }
});