Dynamic Dropdown Laravel 4

Saya ingin membuat dynamic dropdown pada laravel 4 tetapi tidak berjalan. Saya menggunakan firebug untuk mengecek apakah javascript berjalan dan tidak muncul error tapi ketika category dipilih subcategory tidak muncul. mohon bantuannya, terimakasih.

Ini adalah code saya

view

<form method="post" class="form-horizontal">
		  {{Form::open(array('url'=>'tambahtayang','method'=>'POST'))}}
		  		<div class="form-group">
					{{ Form::label('idBioskop', 'Nama Bioskop :', array('class' => 'col-sm-2 control-label')) }}
					<div class="col-sm-10">
						<select id="category" name="category" class="selectpicker">
						<option></option>
		    		        @foreach($bioskop as $bioskops)
		    		        <option value="{{$bioskops->idBioskop}}">{{$bioskops->namaBioskop}}</option>
		    		        @endforeach
		    		    </select>
					</div>
				</div>
				<div class="form-group">
					{{ Form::label('idStudio', 'Studio :', array('class' => 'col-sm-2 control-label')) }}
					<div class="col-sm-10">
						<select id="subcategory" name="subcategory" class="selectpicker">
						<option value=""></option>
		    		    </select>
					</div>
				</div>
				<div class="form-group">
					{{ Form::label('idFilm', 'Judul Film :', array('class' => 'col-sm-2 control-label')) }}
					<div class="col-sm-10">
						{{Form::select('idFilm', $film, null, array('class' => 'selectpicker'))}}
					</div>
				</div>
				<div class="form-group">
					{{ Form::label('jamMulai', 'Jam Mulai :', array('class' => 'col-sm-2 control-label')) }}
					<div class="col-sm-10">
						<input type="time" name="jamMulai" id="jamMulai" >
					</div>
				</div>
				<div class="form-group">
					{{ Form::label('status', 'Status :', array('class' => 'col-sm-2 control-label')) }}
					<div class="col-sm-10">
						<select id="status" name="status" class="selectpicker">
							<option value="Null">Null</option>
		    		        <option value="Now Playing">Now Playing</option>
		    		        <option value="Coming Soon">Coming Soon</option>
		    		    </select>
					</div>
				</div>
				<div class="hr-dashed"></div>
				<div class="form-group">
					<div class="col-sm-8 col-sm-offset-2">
						<a class="btn btn-danger " href="{{ url('tayang') }}">Batal</a>

						<a href="{{ url('tambahdetiltayang') }}" type="button" class="btn btn-default">Next</a>
					</div>
				</div>

				{{Form::close()}}
	</form>

<script src="js/jquery.min.js"></script>
<script type="text/javascript">
    $(document).ready(function() {
        $('select[name="category"]').on('change', function() {
            var stateID = $(this).val();
            if(stateID) {
                $.ajax({
                    url: '/myform/ajax/'+stateID,
                    type: "GET",
                    dataType: "json",
                    success:function(data) {


                        $('select[name="subcategory"]').empty();
                        $.each(data, function(key, value) {
                            $('select[name="subcategory"]').append('<option value="'+ key +'">'+ value +'</option>');
                        });

                    }
                });
            }else{
                $('select[name="subcategory"]').empty();
            }
        });
    });
</script>

Controller

    public function myform()
    {
        $bioskop = Bioskop::where('flag','=',1)->get();
        $film=Film::where('flag','=',1)->lists('judulFilm','idFilm');
        return View::make('admin.tayang.createtayang',compact('bioskop','film'));
    }

    public function myformAjax($id)
    {
        $studio = DB::table('studio')
                    ->where('idBioskop',$id)
                    ->lists('namaStudio','idStudio');
        return json_encode($studio);
    }

Routes

Route::get('tambahtayang',array('before' => 'auth','as'=>'tayang.myform','uses'=>'TayangController@myform'));

Route::get('myform/ajax/{id}',array('as'=>'myform.ajax','uses'=>'TayangController@myformAjax'));