При нажатии кнопки в окне window_chronicle меняется значение переменной

from tkinter import *
from tkinter import ttk
from PIL import Image, ImageTk
def left_but():
            digital_order = digital_order - 1
def right_but():
            digital_order = digital_order + 1
   
def chronicle_of_the_war():
    digital_order = 0     
    main_window.withdraw()
    window_chronicle = Toplevel()
    window_chronicle.title("Патриот")
    window_chronicle.geometry('1500x770')
    window_chronicle.resizable(False,False)
    window_chronicle.configure(bg='gold2')
    right_button = Button(window_chronicle,text='→',font=10,width=6,height=8,command= right_but).pack(side=RIGHT)    
    if 0 > digital_order < 15:
 
        left_button = Button(window_chronicle,text='←',font=10,width=6,height=8,command= left_but).pack(side=LEFT)
 
 
main_window = Tk()
main_window.title("Патриот")
main_window.geometry('1500x770')
main_window.resizable(False,False)
main_window.configure(bg='gold2')
img = PhotoImage(file=r'C:\Users\Admin\Desktop\Patriot\Material\image\image_380x249.png')
Label(main_window,image=img).pack()
button_1 = Button(main_window, text ='Хроника ВОВ',bg='yellow', width=50,height=5, font='Times 11', activebackground='orange',command=chronicle_of_the_war).pack(pady= 20)
button_2 = Button(main_window, text ='Герои ВОВ',bg='yellow', width=50,height=5, font='Times 11', activebackground='orange').pack(pady= 10)
button_2 = Button(main_window, text ='Викторина',bg='yellow', width=50,height=5, font='Times 11', activebackground='orange').pack(pady= 15)
img1 = PhotoImage(file=r'C:\Users\Admin\Desktop\Patriot\Material\image\day_wins.png')
Label(main_window,image=img1).place(x=10, y= 200)
main_window.mainloop()