Lov not doing mandatroy validation

Question

hi i have this lov it does not do required validation even if i set required =true ,am in jdeveloper 11.1.1.6.0,is not checking that validation
<af:selectOneChoice value="#{bindings.Officecode.inputValue}"
                                        label="#{bindings.Officecode.label}"
                                        shortDesc="#{bindings.Officecode.hints.tooltip}"
                                        id="soc9" simple="true" required="true"
                                        contentStyle="width:145px;"
                                        autoSubmit="true">
                      <f:selectItems value="#{bindings.Officecode.items}"
                                     id="si5"/>
                    </af:selectOneChoice>

Answer 1

but this field is been checked when i click the next button,i did not select any value
<af:selectOneChoice
                                          label="Country name"
                                          required="#{bindings.CountryLOV1.hints.mandatory}"
                                          shortDesc="#{bindings.CountryLOV1.hints.tooltip}"
                                          id="soc3" simple="true"
                                          value="#{pageFlowScope.orgDetailsBean.addressBean.countryCode}"
                                          valueChangeListener="#{pageFlowScope.orgDetailsBean.valueChangedcountry}" autoSubmit="true"
                                          contentStyle="width:145px;">
                                        <af:forEach items="#{bindings.CountryLOV1.iteratorBinding.allRowsInRange}"
                                  var="row">
                        <af:selectItem id="tiltddco2" label="#{row.countryname}"
                                       value="#{row.countrycode}"/>
                      </af:forEach>
                      </af:selectOneChoice>