title: flex broken spark image
body: <p>On my air application, I try to load image like this:</p>
  
  <pre><code>var imAc:Image=new Image();
  imAc.source=rootFile+value+"-V-"+label+".png";
  </code></pre>
  
  <p>Sometimes, image source doesn't exist.</p>
  
  <p>In this case, broken icon appear but if this error appear I'd like to change image source </p>
  
  <pre><code> imAc.source= null
  </code></pre>
  
  <p>With mx:Image ioError property exist but I don't find the same with spark image.
  Do you know how to do that?</p>
  
  <p>Thanks</p>