public String delete(Post post) {
    getDao().delete(post);
    return "success";
}

   <ui:repeat value="#{TestMB.entityList}" var="entityList">

        <p>
            #{entityList.name}

            <h:commandLink action="#{TestMB.delete(entityList)}">
                del
                <f:ajax render=":form1"/>
            </h:commandLink>
        </p>
    </ui:repeat>


</h:form>

private String txt1="test";

public String delete() {

    try{
        Thread.sleep(Long.valueOf("10000"));
    }catch(Exception ex){

    }

    txt1="";

    return "";
}

<h:form id="form1">

            #{testMB.txt1}

            <h:commandLink action="#{testMB.delete}">
                del
                <f:ajax render=":form1"/>
            </h:commandLink>
</h:form>

javax.faces.FacesException: <f:ajax> contains an unknown id 'form1' - cannot locate it in the context of the component j_idt51

public List<Entity> getEntityList() {

        //if(entityList == null){
            entityList=getDao().findAll(getPageRequest());
        //}

        return entityList;
    }