看看这段Python代码问题出在哪

照着书上写的，执行时报错（Python2.6）
import wx
class InsertFrame(wx.Frame):
    def __init__(self,parent,id):
        wx.Frame.__init__(self,parent,id,'Frame With Button',size=(300,100))
        panel = wx.Panel(self)
        button = wx.Button(panel,label="Close",pos=(125,20),
                          size=(50,50))
        self.Bind(wx.EVT_BUTTON,self.OnCloseMe,button)
        self.Bind(wx.EVT_CLOSE,self.OnCloseWindow)

    def OnCloseMe(self,event):
        self.Close(True)

    def OnCloseWindow(self,event):
        self.Destroy()

if __name__=='__main__':
    app = wx.PySimpleApp()
    frame = InsertFrame(parent=None,id=-1)
    frame.Show()
    app.MainLoop()
   
报错信息如下：
Traceback (most recent call last):
  File "D:\Python26\test\wx\button.py", line 19, in <module>
    frame = InsertFrame(parent=None,id=-1)
  File "D:\Python26\test\wx\button.py", line 4, in __init__
    wx.Frame.__init__(self,parent,id,'