from Tkinter import *
from tkMessageBox import *
def callback():
if askyesno('Verify', 'Do you really want to quit?'):
showwarning('Yes', 'Quit not yet implemented')
else:
showinfo('No', 'Quit has been cancelled')
errmsg = 'Sorry, no Spam allowed!'
Button(text='Quit', command=callback).pack(fill=X)
Button(text='Spam', command=(lambda: showerror('Spam', errmsg))).pack(fill=X)
mainloop()