title: JSF f:ajax prompt before any action
body: <p>How I can show dialog before any f:ajax action.
  I have code as following:</p>
  
  <pre><code>    &lt;h:commandButton  value="Create Project" styleClass="greyishBtn submitForm" action="#{projectController.delete}"&gt;
            &lt;f:ajax execute="@form"  onevent="function(data) {createProjectEventHandler(data);}" render=":tblProject txtNewProjectName txtNewProjectStartDate taNewProjectDesc"/&gt;
      &lt;/h:commandButton&gt;
  </code></pre>
  
  <p>This code works fine, but I need a confirm dialog before call delete action, I tried onevent, but it only have begin, success and complete events, what I need is confirm dialog before 'begin' event.</p>
  
  <p>Any idea?</p>
  
  <p>Thanks in advance.</p>