How to add a message to a field in a dataTable row?

Question

I have a dataTable with a var "selectedUser". Each row has a 2 fields: username & password, both editable and 2 buttons: save and delete. In the "UsersControllerBean.updateUser" method associated with the update button, I want to be able to add an error message to the field on the corresponding row where the button has been clicked. How can I retrieve the client Id of the field from the "selectedUser" var associated with the dataTable (that I get from the RequestMap) to add the message to it?
Is there an easier way of doing this? (no, thanks no link button!)
Thanks
Fred
               <h:form id="users">
               <h:dataTable border="1" width="100%" value="#{UsersControllerBean.usersList}" var="selectedUser">
                    <h:column>
                         <f:facet name="header">
                                   <h:outputText value="Id"/>
                         </f:facet>
                         <h:outputText value="#{selectedUser.userId}"/>
                    </h:column>
                    <h:column>
                         <f:facet name="header">
                                   <h:outputText value="Name"/>
                         </f:facet>
                         <h:inputText id="username" required="true" value="#{selectedUser.username}"/>
                         <h:message for="username" style="color: red"/>
                    </h:column>
                    <h:column>
                         <f:facet name="header">
                                   <h:outputText value="Password"/>
                         </f:facet>
                         <h:inputText id="password" value="#{selectedUser.password}"/>
                         <h:message for="password" style="color: red"/>
                    </h:column>
                    <h:column>
                         <f:facet name="header">
                                   <h:outputText value="Actions"/>
                         </f:facet>
                         <h:commandButton value="Save" action="#{UsersControllerBean.updateUser}"/>
                         <f:verbatim>��</f:verbatim>
                         <h:commandButton value="Delete" action="#{UsersControllerBean.deleteUser}" immediate="true"/>
                    </h:column>
               </h:dataTable>
               </h:form>

Answer 1

Dear Friends,
Finally, I got the answer.
I required to add the messages to error log for invoice. Error log is displayed in Tree format.
The error log getting displayed while processing invoice with help of table VBSK.
We can update the VBSK table information with required message to put in log.
Best regards,
Amol Chaudhari.