code is like this:

main.jsp:
<a4j:commandLink value="Login" action="login" reRender="main" />
<h:panelGroup id="main">
<a4j:include viewId="/page/greeting.jsp" />
</h:panelGroup>

greeting.jsp:
<a4j:commandLink value="Login" action="login" reRender="main" />

In main.jsp, there are 2 commandLinks, however, only the second works. When click the first one, the whole page will be REDIRECTED to login page. I just want to implement menu like UI. I don't know how to do with...