title: wicket download link clear feedback panel
body: <p>I have couple of drop downdowns and a download link button. Based on the user selection, i get the file to be downloaded. if the user did not make a selection I show an error on the feedback panel. if the user then makes a selection and clicks on download link it works fine, but the previous feedback message is still visible. How do I clear it. </p>
  
  <p>onclick of the download link, i tried the following, but no use</p>
  
  <pre><code>FeedbackMessages me = Session.get().getFeedbackMessages(); 
  me.clear();
  </code></pre>