<pe:session onexpire="PF('sessionDialog').show()"
                onexpired="PF('sessionDialog').hide();PF('sessionExpiredDialog').show()"
                reactionPeriod="60"/>

    <p:dialog widgetVar="sessionDialog" header="Session Warning">
        <p>
            Your session is about to expire.
        </p>
        <h:form>
            <p:commandButton value="Keep my session alive." onsuccess="PF('sessionDialog').hide()"/>
        </h:form>
    </p:dialog>

    <p:dialog widgetVar="sessionExpiredDialog" header="Session Expired">
        <p>
            Your session has expired.
        </p>
    </p:dialog>