How to not reRender in a4j:commandButton if validation error

[dxxvi]

I have

<a4j:form>
...
 <a4j:commandButton ... reRender="box" />
</a4j:form>

<h:panelGroup id="box">...</h:panelGroup>

I don't want the box to be re-rendered if there is some validator exception. How could I achieve that?

[ilya_shaikovsky]

You should point reRender to some bean property and(List) and fill this list in your action or listener. In case validation fail - list will be empty ;)