JSF selectManyListbox Issue?

[Yancy cheng]

Hi,all. I meet the problem that puzzled me a long time, please help.
ics_ui_cascadeCombo.xhtml

<a4j:region id="#{id}_cust_cascade_region">
		<h:inputHidden id="#{id}_hidden_main_cust_code" value="#{customerBean.mainCustomerCode}" />
	
		<a4j:outputPanel id="#{id}_cust_main_panel">
			<csui:custCombo id="#{id}_main" styleClass="#{styleClass}" haveDropDown="#{haveDropDown}" onItemSelectAction="#{id}_test();"/>
		</a4j:outputPanel>
		
		<a4j:jsFunction name="#{id}_searchDivision" action="#{customerBean.doRetreiveDivisionSelectItemList}" oncomplete="#{id}_afterRetreiveDivisions();" reRender="#{id}_cust_cascade_select"></a4j:jsFunction>
		
		<a4j:outputPanel id="#{id}_cust_cascade_panel">
			<h:selectManyListbox id="#{id}_cust_cascade_select" value="#{divisionList}" styleClass="#{divisionClass}" immediate="true">
				<f:selectItems value="#{customerBean.divisionSelectItemList}" />
			</h:selectManyListbox>
		</a4j:outputPanel>
		
		<script type="text/javascript">
		//<![CDATA[
			function #{id}_afterRetreiveDivisions() {
			}
			
			function #{id}_test() {
				alert(jQuery('input[id$=#{id}_main_oid_hidden]').val());
				jQuery('input[id$=#{id}_hidden_main_cust_code]').val(jQuery('input[id$=#{id}_main_oid_hidden]').val());
				#{id}_searchDivision();
			}
		//]]>
		</script>

CascadeComboBean.java

public class CascadeComboBean {
	private  List<String> resultList = new ArrayList<String>();

	public List<String> getResultList() {
		return resultList;
	}

	public void setResultList(List<String> resultList) {
		this.resultList = resultList;
	}
}

test.xhtml

<ui:define name="ics_body">
		<a4j:form>
			<ics:icsCascadeCombo id="abcd" divisionList="#{cascadeComboBean.resultList}"></ics:icsCascadeCombo>
		</a4j:form>
	</ui:define>

i make sure that jQuery('select[id$=abcd_cust_cascade_select]').val() has items which i selected. but there is no value pass to server. i found log that seems have a jsf problem:
Processing new Request!
before - RESTORE_VIEW(1)
after - RESTORE_VIEW(1)
before - APPLY_REQUEST_VALUES(2)
after - APPLY_REQUEST_VALUES(2)
j_id37:abcd_cust_cascade_select: Invalid value-j_id37:abcd_cust_cascade_select: Invalid value
before - RENDER_RESPONSE(6)
after - RENDER_RESPONSE(6)
j_id37:abcd_cust_cascade_select: Invalid value-j_id37:abcd_cust_cascade_select: Invalid value
Information for the field(s) marked red below is incorrect. Please amend and try again.-Information for the field(s) marked red below is incorrect. Please amend and try again.
Done with Request!

Please help, thank you very much.