Select2 demo

by a13xs

HTML

<script src="https://rawgit.com/select2/select2/master/dist/js/select2.js"></script>
<link rel="stylesheet" href="https://rawgit.com/select2/select2/master/dist/css/select2.min.css">
<select id="example" multiple="multiple" style="width: 300px">
<optgroup label="Social media">
  <optgroup label="Facebook">
     <option value="JAN">January</option>
      <option value="FEB">February</option>
      <option value="MAR">March</option>
      <option value="APR">April</option>
  </optgroup>
  <optgroup label="Twitter">
     <option value="JAN">January</option>
      <option value="FEB">February</option>
      <option value="MAR">March</option>
      <option value="APR">April</option>
  </optgroup>
</optgroup>
</select>

JavaScript

$('#example').select2({
    placeholder: 'Select a month'
});