<select id="MyOptionBox" name="MyOptionBox" ">
    <option value="0" selected >Option 0</option>
    <option value="1" >Option 1</option>
  </select>
					
<script>
function myFunction() {
  var ActiveElement = document.activeElement.id;
  if (ActiveElement != "MyOptionBox")
    Do something...
}
</script>