as i said in my subject ajaxvalidator is working but the shown message is not good to see at all
here is my code

<!-- Start of Modal panel of Add New Task -->
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<rich:modalPanel id="id_add_task" rendered="false" showWhenRendered="true" binding="#{task_page_site_admin.binding_modal_panel_add_task}" width="400" height="400" autosized="true" resizeable="false">
 <f:facet name="header">
 <h:panelGroup>
 <h:outputText value="Add New Task"></h:outputText>
 </h:panelGroup>
 </f:facet>
 <f:facet name="controls">
 <h:panelGroup>
 <h:graphicImage value="close.png" styleClass="hidelink" id="hidelink_update_ressource"/>
 <rich:componentControl for="update_ressource" attachTo="hidelink_update_ressource" operation="hide" event="onclick"/>
 </h:panelGroup>
 </f:facet>

<h:form>

<table width="403" height="284" border="0">


 <tr>

 <td>Descrption</td>
 <td><h:inputText required="true" id="id_add_new_task_description" value="#{task_page_site_admin.add_task_members_.task_description}">
 <f:validateLength minimum="3" maximum="12"/>
 <rich:ajaxValidator event="onblur"/>

 </h:inputText>
 <rich:message for="id_add_new_task_description"/>

 </td>
 </tr>
 <tr>
 <td>Ressource Allocated</td>
 <td><rich:comboBox required="true" value="#{task_page_site_admin.add_task_members_.selected_ressource}">
 <f:selectItems value="#{task_page_pole_manager.add_task_members_.available_ressources}"/>

 </rich:comboBox></td>
 <td>Priority</td>
 <td><rich:comboBox value="#{task_page_site_admin.add_task_members_.priority}"><f:selectItem itemValue="High" /><f:selectItem itemValue="Medium" /><f:selectItem itemValue="Low" /><f:selectItem itemValue="Critical" /></rich:comboBox></td>
 </tr>
 <tr>
 <td>Period</td>
 <td>

 <h:inputText id="id_add_new_task_period" required="true" value="#{task_page_site_admin.add_task_members_.period}" >
 <f:validateLength minimum="3" maximum="12"/>
 <rich:ajaxValidator event="onblur"/>

 </h:inputText>

 <rich:message for="id_add_new_task_period"/>



</td>
 <td>Cathegory</td>
 <td><rich:comboBox value="#{task_page_site_admin.add_task_members_.task_type}" >
 <f:selectItem itemValue="Spec"/>
 <f:selectItem itemValue="Archi"/>
 <f:selectItem itemValue="Design"/>
 <f:selectItem itemValue="Implem"/>
 <f:selectItem itemValue="Integ"/>
 <f:selectItem itemValue="Verif"/>
 <f:selectItem itemValue="---------------" itemDisabled="true"/>
 <f:selectItem itemValue="Acquisition"/>
 <f:selectItem itemValue="Factory Support"/>
 <f:selectItem itemValue="---------------" itemDisabled="true"/>
 <f:selectItem itemValue="PM"/>
 <f:selectItem itemValue="QA"/>
 <f:selectItem itemValue="CM"/>
 <f:selectItem itemValue="SCM"/>
 <f:selectItem itemValue="---------------" itemDisabled="true"/>
 <f:selectItem itemValue="Training"/>
 <f:selectItem itemValue="Holidays"/>
 <f:selectItem itemValue="Training"/>
 <f:selectItem itemValue="---------------" itemDisabled="true"/>
 <f:selectItem itemValue="Others"/>
 </rich:comboBox></td>
 </tr>
 <tr>
 <td>Status</td>
 <td><rich:comboBox value="#{task_page_site_admin.add_task_members_.task_status}" ><f:selectItem itemValue="Open" /><f:selectItem itemValue="Running" /><f:selectItem itemValue="Pending" /><f:selectItem itemValue="Closed" /></rich:comboBox></td>
 </tr>
 <tr>
 <td>Planned Start Date</td>
 <td><rich:calendar datePattern="yyyy-MM-d" value="#{task_page_site_admin.add_task_members_.planned_start_date}"/></td>
 <td>Planned End Date</td>
 <td><rich:calendar datePattern="yyyy-MM-d" value="#{task_page_site_admin.add_task_members_.planned_end_date}" /></td>
 </tr>
 <tr>
 <td>Planned Workload</td>
 <td>
 <h:inputText required="true" id="id_add_new_task_planned_workload" value="#{task_page_site_admin.add_task_members_.planned_workload}">
 <f:validateLength minimum="3" maximum="12"/>
 <f:validateLongRange></f:validateLongRange>
 <rich:ajaxValidator event="onblur"/>
 </h:inputText>
 <rich:message for="id_add_new_task_planned_workload"/>
 </td>
 </tr>

</table>



<p> </p>
<table width="556" border="0">
 <tr>
 <td width="246"><h:commandButton value="Confirm" action="#{task_page_site_admin.confirm_add_new_task}" /></td>
 <td width="246"><h:commandButton immediate="true" value="Cancel" action="#{task_page_site_admin.cancel_show_modal_panel_x}" />
 </tr>
</table>



</h:form>
</rich:modalPanel>





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