                         <p:column headerText="Bill No" rendered="false"
                                              sortBy="#{bill.deptId}" filterBy="#{bill.deptId}" >                                
                                        <h:outputLabel   value="#{bill.deptId}"/>
                                    </p:column> 
                                    <p:column headerText="Billed For" sortBy="#{bill.toDepartment.name}" filterBy="#{bill.toDepartment.name}" filterMatchMode="contains" >        