<a4j:jsFunction name="updateList" reRender="buttonsPanel" actionListener=# {myController.refresh}" />

<a4j:outputPanel id="buttonsPanel">
    <h:commandButton id="myButton" onclick="return confirm('Are you sure you want to perform this operation');" value="Save" action="#{myController.doSave}" styleClass="#{myController.isReady ? 'ShowGreen' : 'ShowRead'}" immediate="true">
</a4j:outputPanel>