关于用java获取 arcims 发布的地图和layer

<P>napframe is a sub page of the frameset, and i want to call the map in mapframe from another sub page. but I cann't get the imsmap, why?</P>
<P>var layer = parent.MapFrame.IMSMap.getSelectedLayer();</P>

即如何获取mapframe中的地图对象。mapframe 是用ARCIMS发布的地图显示的子页面