[walik]

<input type="checkbox" onclick="change();" value="1" />
<select style="display: none;" id="select">
  <option>Option 1</option>
  <option>Option 2</option>
  <option>Option 3</option>
</select>
  <script>
function change() {
  var s = document.getElementById('select');
  s.style.display == 'none' ? s.style.display = '' : s.style.display = 'none';
}
  </script>