title: Bootstrap Select Dropdown on change open another Bootstrap Select Dropdown
body: <p>I have 2 bootstrap select picker. How i automatically open adjacent drop down when one drop down is selected.</p>
  
  <pre><code>&lt;select class="selectpicker" data-live-search="true" data-size="10" id="letterdropdownboxes1" name="letterdropdownboxes1"&gt;
  &lt;option value=""&gt;&lt;/option&gt;
  &lt;option value="A"&gt;A&lt;/option&gt;
  &lt;option value="B"&gt;B&lt;/option&gt;
  &lt;/select&gt;
  
  &lt;select class="selectpicker" data-live-search="true" data-size="10" id="letterdropdownboxes2" name="letterdropdownboxes2"&gt;
  &lt;option value=""&gt;&lt;/option&gt;
  &lt;option value="A1"&gt;A1&lt;/option&gt;
  &lt;option value="B1"&gt;B1&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>I tried below code but not working.</p>
  
  <pre><code>$("#letterdropdownboxes1").on("change", function(e) {
      var optionSelected = $("option:selected", this);
      var valueSelected = this.value;
      if (valueSelected != null) {
          $('#letterdropdownboxes2').selectpicker('toggle');
      }
  });
  </code></pre>