title: How to use RichFaces a4j:commandButton not using submit
body: <p>I have an <code>a4j:commandButton</code> which looks like this</p>
  
  <pre><code>    &lt;a4j:commandButton id="stopBtn" type="button" reRender="lastOp"
    action="#{MyBacking.stop}" value="Stop" /&gt;
   &lt;/a4j:commandButton&gt;
  </code></pre>
  
  <p>When the app is deployed, and the button clicked, the stop() method is not being called.  All the <code>a4j:commandButton</code> examples refer to forms, but this button is not in a form - it's a button the user is going to use to cause the server to run some back-end logic.  At the moment, the method is</p>
  
  <pre><code>    public void stopNode() {
   logger.info("STOPPING");
   setLastOp("Stopped.");
  }
  </code></pre>
  
  <p>Other methods which don't use this type of button are updating the lastOp field, but I'm not seeing anything on the console with this one.  Am I right to cast this as a button?  Should I put this in a <code>h:form</code> tag?</p>
  
  <p>The firebug console says:</p>
  
  <pre><code>this._form is null
  </code></pre>
  
  <p>which I don't understand.</p>
  
  <p>Any help well appreciated.</p>