问可重复的tkinter按钮命令...？

EN

from Tkinter import *
__author__ = 'Super'

def close_program():
    root.destroy()


def number_checker():
    global vehicle_distance
    global vehicle_time
    try:
    vehicle_distance = float(vehicle_distance)
    correct_text_distance()
except ValueError:
    failed_text_distance()
try:
    vehicle_time = float(vehicle_time)
    correct_text_time()
except ValueError:
    failed_text_time()


def failed_text_time():
    global root
    root = Tk()
    root.title("Fatal Error")
    root.geometry("300x30")

    error_label = Label(root, text="Please input an integer for the field 'time'")
    error_label.pack()

    ok_button = Button(root, text="Ok", command=close_program)
    ok_button.pack()
    root.mainloop()