e32.ao_sleep(5) stops the application?

[llapplecn]

This is my code.I want to show the image 5 seconds and show the text "Hello world" . It works correctly as a script in Python application. However, when it is changed to a stand-alone application. It stop at "e32.ao_sleep(5)". As a result , i can't show the text(hello world)..........I used 2 days to check what is the problem...but I can't find the answer..... In the Python application, there is no error.........anybody can help me?

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from appuifw import *
from key_codes import *
from graphics import Image
import e32

app.screen = 'full'
app.body = c= Canvas()
lock = e32.Ao_lock()

def draw():
c.blit(Image.open(u"C:\\Nokia\\Images\\game.png"))
e32.ao_sleep(5)
appuifw.note(u"testing 3",'info')

running = 1

def handle_exit():
appuifw.app.set_exit()

app.exit_key_handler= handle_exit

def text():
appuifw.note(u"testing 2",'info')
textN=appuifw.Text()
textN.add(u"Hello World")
appuifw.app.body =textN
lock.wait()
app.exit_key_handler= handle_exit

draw()
while running:
appuifw.note(u"testing 1",'info')
text()
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