def handle_captcha(url, headers={}):
    root = Tk()
    root.title('Enter captcha')
    var = StringVar()
    def quit():
        var.set('')
        root.destroy()
    def on_enter(event):
        root.destroy()
    root.protocol('WM_DELETE_WINDOW', quit)
    request = urllib2.Request(url, headers=headers)
    response = urllib2.urlopen(request)
    image_data = StringIO(response.read())
    photo_image = ImageTk.PhotoImage(Image.open(image_data))
    captcha_img = Label(root, image=photo_image)
    captcha_img.pack()
    captcha_input = Entry(root, width=10, textvariable=var)
    captcha_input.pack()
    captcha_input.focus()
    captcha_input.bind('<Return>', on_enter)
    submit = Button(root, text='Submit', command=root.destroy)
    submit.pack()
    root.mainloop()
    return var.get()