event.source.parent.getWidget("inner").getWidget("doplist-inner")

[Christina <le...@hotmail.com>]

I want the content of  "droplist-inner" changed every time value of "droplist-outer" changed.
So I use this " event.source.parent.getWidget("inner").getWidget("doplist-inner") " to get widget "droplist-inner" from "droplist-outer"
then  use "setSelectionList" to set its list content.
but every time there is error:    org.apache.avalon.framework.CascadingRuntimeException: Error invoking JavaScript event handler

Would anybody give me some idea why and how to fix it????
Thanks!!

<wd:repeater id="outer">
.
  <wd:widgets>
       <wd:field id="droplist-outer">
       <wd:repeater id="inner"> 
              <wd:widgets>
                   <wd:field id="droplist-inner">