Here is my code

<a:form ajaxSingle="true" ajaxSubmit="true">

    <table>

        <tr>

            <td>

                <s:decorate template="layout/edit.xhtml" id="decBin"

                    rendered="#{!recInfoHome.instance.recToDefaultLoc}">

                    <ui:define name="label">Bin</ui:define>

                    <h:selectOneMenu id="binEdit" immediate="true"

                        value="#{recViewManager.sysRecBinId}"

                        required="true">

                        <f:selectItem itemValue="" itemLabel="--Select--" />

                        <f:selectItems value="#{myDBUtil.sysRecBinLuList}"/>       

                        <a:support event="onchange" actionListener="#{recViewManager.assignSysRecBin()}" ajaxSingle="true"/>                         

                    </h:selectOneMenu>

                </s:decorate>

            </td>

        </tr>           

    </table>           

</a:form>

The method assignSysRecBin is never getting called. I have tried many differnt ways but nothing helped me.