Tenho que exibir mensagens de regras de negocio, para isto eu criei o seguinte
<rich:modalPanel showWhenRendered="#{pedidoVendaControle.modalErro}" id="msgsErros" width="300" height="150" >
<f:facet name="header">
<h:outputText value="..: ATENÇÂO ..:" />
</f:facet>
<f:facet name="controls">
<h:panelGroup>
<h:graphicImage value="/imagens/close.png" alt="" styleClass="hidelinkCloseMsg" id="hidelinkCloseMsg" />
<rich:componentControl for="msgsErros" attachTo="hidelinkCloseMsg" operation="hide" event="onclick" />
</h:panelGroup>
</f:facet>
<a4j:outputPanel id="panelErros" >
<rich:messages ajaxRendered="true" styleClass="msgErro" />
<!-- h:messages errorStyle="color: red" infoStyle="color: green" layout="table" showSummary="true" showDetail="true" globalOnly="true" / -->
</a4j:outputPanel>
</rich:modalPanel>
FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO,MessagesGlobal.VALOR_TOTAL_PEDIDO_MAIOR_QUE_SALDO_CLIENTE,null));
setModalErro(true);