title: how can I add event to richfaces fileUpload "on clear"
body: <p>there are clear, clear all buttons on richfaces fileUpload component. </p>
  
  <pre><code>&lt;rich:fileUpload id="quoteFile" tabindex="10" listHeight="80" maxFilesQuantity="1" onuploadcanceled="" 
   clearControlLabel=""
   clearAllControlLabel=""
   acceptedTypes="xml"
   fileUploadListener="#{loadSaveQuotes.uploadListener}"&gt;     
   &lt;a4j:support event="onuploadcanceled" action="#{loadSaveQuotes.clearUploadData}" reRender="footer"  /&gt;
  &lt;/rich:fileUpload&gt;
  </code></pre>
  
  <p>all I want to are:</p>
  
  <p>1, remove the both buttons so that end user cannot click it. as I set clearControlLabel to "", and clearAllControlLabel to "", but only clearControlLabel is hidden. still have clear All Control appear as [x] button and I still click it </p>
  
  <p>2, if I cannot remove these button, so how do I take control of them. like add an event listener to that on clear event. I added an a4j:support event but it do not trigger when I click clear button.</p>
  
  <p>many thanks for your contribute.</p>