Change sibling repeater's droplist??

[Christina]

I want to change "doplist-inner" in all rows of repeater "inner" whenever the value of "droplist-outer" changes, but because they are in different level, it seems you cannot use javasript event.source.parent.getWidget("inner").getWidget("droplist-inner") from "droplist-outer"'s <wd:on-value-changed>. every time there is error: java.lang.RuntimeException: Repeater: Row id is not a valid integer: droplist-inner .   Would anybody give me some idea 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">