Make a Rocket UI in new DisplayRegion, but I can't click.

This is my code:

# -*- coding: utf-8-*-

from panda3d                        import rocket
from panda3d.rocket					import *
from pandac.PandaModules            import WindowProperties, loadPrcFileData, loadPrcFile
import sys
loadPrcFile(sys.path[0]+"/Config.prc")

import direct.directbase.DirectStart
from direct.showbase.DirectObject	import DirectObject
from pandac.PandaModules			import WindowProperties
from pandac.PandaModules			import MouseWatcher

from cityedit                       import CityEdit

# 建立另一个显示区域
base.win.removeAllDisplayRegions()

dr = base.win.makeDisplayRegion(0, 0.75, 0, 1)
dr.setClearColorActive(True)
dr.setClearDepthActive(True)
dr.setCamera(base.cam)
base.mouseWatcherNode.setDisplayRegion(dr)

drui = base.win.makeDisplayRegion(0.75, 1, 0, 1)
myMouseWatcher = MouseWatcher()
base.mouseWatcher.getParent().attachNewNode(myMouseWatcher)
myMouseWatcher.setDisplayRegion(drui)

cityedit = CityEdit()

rocket.LoadFontFace("HiraginoSansGBW6.otf")

r = RocketRegion.make('pandaRocket', base.win)
r.setActive(1)

ih = RocketInputHandler()
base.mouseWatcher.attachNewNode(ih)
r.setInputHandler(ih)

context = r.getContext()

context.LoadDocument('main_menu.rml').Show()

run()

I use dr(left) render 3d model, and use rdui(right) display rocket ui. But I can’t see hover effect.

use one display region for UI.

When I use one display region, click on the UI will respond to click events other codes.