Changing Language in JSF page

Question

I found a problem in my application when I needed to change the language of my login page . My managed bean is:

@ManagedBean(name="langueApp")
@SessionScoped
public class LangueApp {


public String activerFR() {
    FacesContext context = FacesContext.getCurrentInstance();
    context.getViewRoot().setLocale(Locale.FRENCH);
    return null;
    }

    public String activerEN() {
    FacesContext context = FacesContext.getCurrentInstance();
    context.getViewRoot().setLocale(Locale.ENGLISH);
    return null;
    }

and in my login page the code related to the change of language is :

<p:commandLink ajax="false" value="#{langueApp.activerFR()}"         immediate="true"><p:graphicImage library="images" name="francais.jpg" style="border:0px"/>
</p:commandLink>

Same thing for english.

The problem is when executing and clicking on the image to change the language everything works fine but when re-clicking on the previous image no change is occured , the language don't change, is there any solution for this ?