title: check if field value has changed with jquery
body: <p>I want to conastantly check if the value changes.. So if the user selects a new value in an input form I want to run some js code..</p>
  
  <pre><code>&lt;div class="select2-container country_to_state country_select" id="s2id_billing_country" style="width: 100%;"&gt;
      &lt;a href="javascript:void(0)" class="select2-choice" tabindex="-1"&gt;
          &lt;span class="select2-chosen" id="select2-chosen-1"&gt;Schweiz&lt;/span&gt;
          &lt;abbr class="select2-search-choice-close" /&gt;
          &lt;span class="select2-arrow" role="presentation"&gt;
      &lt;b role="presentation"/&gt;
      &lt;/span&gt;
      &lt;/a&gt;
      &lt;label for="s2id_autogen1" class="select2-offscreen"&gt;Land *&lt;/label&gt;
      &lt;input class="select2-focusser select2-offscreen" type="text" aria-haspopup="true" role="button" aria-labelledby="select2-chosen-1" id="s2id_autogen1" /&gt;
  &lt;/div&gt;
  &lt;select name="billing_country" id="billing_country" class="country_to_state country_select " tabindex="-1" title="Land *" style="display: none;"&gt;
      &lt;option value=""&gt;Land auswählen…&lt;/option&gt;
      &lt;option value="DE" selected="selected"&gt;Deutschland&lt;/option&gt;
      &lt;option value="CH"&gt;Schweiz&lt;/option&gt;
      &lt;option value="AT"&gt;Österreich&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>I've tried this so far (doesn't work)</p>
  
  <pre><code>$('#select2-chosen-1').change(function() {
      alert("change");
  });
  </code></pre>