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

  Launch Modal

</button>

​

<!-- Modal -->

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

  <div class="modal-dialog" role="document">

    <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>

      <div class="modal-body">

        ...

      </div>

      <div class="modal-footer">

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

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

      </div>

    </div>

  </div>

</div>