<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.js"></script>
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
  <script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>

  <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/js/bootstrap-multiselect.js"></script>
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-multiselect/0.9.15/css/bootstrap-multiselect.css">


<div class="side">
  <div class='cont'>
    <select id="multiple-checkboxes" multiple="multiple">
        <option value="php">asdlkjfhalsdfjalsd;fha;sldkfja;sldkfja;lsdkjf;alsdkfja;sldkfja;sldkjfa;lsdkfja;lsdkfja;lsdkjf;al</option>
        <option value="javascript">JavaScript</option>
        <option value="java">Java</option>
        <option value="sql">SQL</option>
        <option value="jquery">Jquery</option>
        <option value=".net">.Net</option>
    </select>
    <div class='bottom'>
      <button> Apply</button>
    </div>
  </div>
</div>
.side {
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  background-color: red;
  height: 100%;
}

.cont {
  padding: 20px;
  position: absolute;
  overflow-y: auto;
  height: 90%;
}

.bottom {
  height: 10%;
  bottom: 0;
  position: absolute;
}
    $(document).ready(function() {
        $('#multiple-checkboxes').multiselect({
          includeSelectAllOption: true,
          maxHeight: 350,
          dropRight: true,
        });
    });

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.