get the child object in a WTDocument via webject

Hi Guys,

How can we do to get the child object in a WTDocument via webject?

<%@page language="java"%><%@taglib uri="http://www.ptc.com/infoengine/taglib/core" prefix="ie"%>  <%String wcAdapter = com.infoengine.au.NamingService.getVMName();%><ie:webject name="Query-Objects" type="OBJ">    <ie:param name="INSTANCE" data="<%=wcAdapter%>"/>    <ie:param name="TYPE" data="wt.doc.WTDocument"/>     <ie:param name="GROUP_OUT" data="resultQuery"/>     <ie:param name="OBJECT_REF" data="$(@FORM[0]obid[0])"/>     <ie:param name="ATTRIBUTE" data="number"/></ie:webject><%           final String strDirection="usedBy";
%><ie:webject name="Query-Links" type="OBJ">    <ie:param name="INSTANCE" data="<%=wcAdapter%>"/>    <ie:param name="GROUP_OUT" data="resultLink"/>    <ie:param name="DIRECTION" data="<%=strDirection%>"/>    <ie:param name="OBJECT_REF" data="${resultQuery[0]obid[0]}"/>     <ie:param name="ATTRIBUTE" data="*"/>    <ie:param name="TYPE" data="wt.doc.WTDocumentUsageLink"/></ie:webject>  <ie:webject name="Return-Groups" type="GRP">    <ie:param name="GROUP_IN" data="*"/></ie:webject>   

Thanks.