title: jQuery - Detect value change on hidden input field
body: <p>I have a hidden text field whose value gets updated via an AJAX response.</p>
  
  <pre><code>&lt;input type="hidden" value="" name="userid" id="useid" /&gt;
  </code></pre>
  
  <p>When this value changes, I would like to fire an AJAX request. Can anyone advise on how to detect the change?</p>
  
  <p>I have the following code, but do not know how to look for the value:</p>
  
  <pre><code>$('#userid').change( function() {  
      alert('Change!'); 
  }) 
  </code></pre>