title: p:fileUpload not working inside p:dialog
body: <p>I'm getting wrong or what, the same code for p:fileUpload works fine, but when I put p:fileUpload into p:dialog, it is not working.</p>
  
  <pre><code>&lt;p:dialog id="confirmDialog"   appendToBody="true"
                     header="MAJ Fichier FMD"  widgetVar="confirmation"&gt;  
             &lt;h:form enctype="multipart/form-data" &gt;
             &lt;h:panelGrid columns="1" cellpadding="5"&gt;
                       &lt;p:fileUpload  
                       auto="true"                 
                       fileUploadListener="#{parserXls.handleFileUploadFMD()}"
                       sizeLimit="2097152"
                       label="Choose"
                       allowTypes="/(\.|\/)(pdf)$/"
                       description="Images"/&gt;
                       &lt;p:commandButton id="OK" value="OK" onclick="confirmation.hide()" type="button" /&gt; 
                       &lt;/h:panelGrid&gt; 
                  &lt;/h:form&gt;                  
          &lt;/p:dialog&gt;  
  </code></pre>
  
  <p>What is the problem here?</p>