WorldViz User Forum - Error Changing Scenes

I'm trying to have my program change scenes once I enter a proximity sensor. I keep receiving an error. Any ideas what i'm doing wrong? :confused:
Code:
import viz

import vizact

import vizproximity



viz.setMultiSample(4)

viz.go()



############# Movement Control Code###################

#Script to control viewpoint with keyboard arrow keys

MOVE_SPEED = 900

TURN_SPEED = 60



def updatecar():

        #move view forward and backward

        if viz.key.isDown(viz.KEY_UP):

                        view.move([MOVE_SPEED*viz.elapsed(),0,0],viz.BODY_ORI)

        if viz.key.isDown(viz.KEY_DOWN):

                        view.move([-MOVE_SPEED*viz.elapsed(),0,0],viz.BODY_ORI)

        if viz.key.isDown(viz.KEY_TAB):

                        view.move([0,MOVE_SPEED*viz.elapsed(),0],viz.BODY_ORI)

        if viz.key.isDown(viz.KEY_SHIFT_L):

                        view.move([0,-MOVE_SPEED*viz.elapsed(),0],viz.BODY_ORI) 



        #rotate body of view left and right

        if viz.key.isDown(viz.KEY_RIGHT):

                        view.setEuler([TURN_SPEED*viz.elapsed(),0,0],viz.BODY_ORI,viz.REL_PARENT)

        elif viz.key.isDown(viz.KEY_LEFT):

                        view.setEuler([-TURN_SPEED*viz.elapsed(),0,0],viz.BODY_ORI,viz.REL_PARENT)

vizact.ontimer(0,updatecar)



########### Viewpoint Code #################

#Start collision detection

viz.MainView.collision( viz.ON )

view = viz.MainView



#Get rid of gravity. 

viz.MainView.gravity(0)



#Set the viewpoint.

viz.MainView.setPosition(88,0,-443)



#Viewpoint

view = viz.MainView



#Actual Viewpoint

view.setPosition([-7034, 200, -10775])

view.setEuler([90, 0, 0])



mars = viz.add('gallery.osgb',scene = viz.Scene1)

viz.addChild('dojo.osgb',scene=viz.Scene2)



manager = vizproximity.Manager()

manager.setDebug(True)

manager.addTarget( vizproximity.Target(viz.MainView) )



# Create sensor using bounding box of node

node = viz.addChild('plant.osgb',pos=(-4034, 0, -10775),scale=(1000,1000,1000))

node.addAction(vizact.spin(0,1,0,45,viz.FOREVER))

sensor = vizproximity.addBoundingBoxSensor(node)

manager.addSensor(sensor)



def changeScene(scene):

        viz.MainWindow.setScene(scene)

        if scene == viz.Scene2:

                viz.MainView.setPosition([0,1.8,0])

                viz.MainView.setEuler([90,0,0])

        

manager.onEnter(None, changeScene)