Tk.quit() now working!

[al pacino]

i have a weired problem with button widget in Tkinter
the callback function(Tk.quit()) for button widget is not working! when
i 'press' the button
the GUI hangs.
 code for displaying a 'button objec':
###################
import Tkinter
top=Tkinter.Tk()
button=Tkinter.Button(top,text='press me',command=top.quit)#callback to
end the appllication
button.pack()
Tkinter.mainloop()
###################
any comments?