<!-- Button trigger modal -->

        <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">

            Launch demo modal

        </button>

​

        <!-- Modal -->

        <div class="modal fade" id="exampleModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true">

            <div class="modal-dialog">

​

                <div class="modal-content">

                    <div class="modal-header">

                        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>

                        <button type="button" class="close" data-dismiss="modal" aria-label="Close">

                            <span aria-hidden="true">&times;</span>

                        </button>

                    </div>

                    <form action="" method="post">

                        <div class="modal-body">

                            <select class="select" data-filter="true" required>

                                <option value="" selected></option>

                                <option value="1">One</option>

                                <option value="2">Two</option>

                                <option value="3">Three</option>

                                <option value="4">Four</option>

                                <option value="5">Five</option>

                                <option value="6">Six</option>

                                <option value="7">Seven</option>

                                <option value="8">Eight</option>

                                <option value="9">Nine</option>

                                <option value="10">Ten</option>

                            </select>

                        </div>

                        <div class="modal-footer">

                            <button type="button" class="btn btn-secondary" data-dismiss="modal">

                                Close

                            </button>

                            <button type="submit" class="btn btn-primary">Save changes</button>

                        </div>

                    </form>

                </div>

            </div>

        </div>