title: How to overwrite the default behaviour of the onchange event of a FilteringSelect dojo widget?
body: <p>I have the following code:</p>
  
  <pre><code>dijit.byId('patient').onchange(function(event){
        var term=dijit.byId('patient').get('value');                                                             
        patientList.url = ".calendar/search-patient?term="+term;
        patientList.close();                                  
  })
  </code></pre>
  
  <p>What I am trying to do is to overwrite the default behaviour of the "onchange" event of a FilteringSelect dojo widget. The problem is that I get the error: "<em>This deferred has already been resolved</em>". </p>
  
  <p>How could I overwrite the default behaviour of the "onchange" event? Thank you                                 </p>