Remove dropdown functionality from the element.
Examples
sample
<button class="gj-button-md" onclick="dropdown.destroy()">Destroy</button>
<select id="dropdown" width="200">
<option value="1">One</option>
<option value="2" selected>Two</option>
<option value="3">Three</option>
</select>
<script>
var dropdown = $('#dropdown').dropdown();
</script>