Tkinter python 3.8 comboboxes in loop。如何在添加到列表时纠正错误的选择？

import tkinter as tk
from tkinter import messagebox

def validate_selection(event):
    selected_value = combobox.get()
    if selected_value not in ["Option 1", "Option 2", "Option 3"]:
        messagebox.showerror("Error", "Invalid selection!")
        combobox.set("Default Option")

def add_to_list():
    selected_value = combobox.get()
    if selected_value not in ["Option 1", "Option 2", "Option 3"]:
        messagebox.showerror("Error", "Invalid selection!")
        combobox.set("Default Option")
    else:
        correct_selections.append(selected_value)

# 创建窗口
window = tk.Tk()

# 创建comboboxes
combobox = tk.ttk.Combobox(window, values=["Option 1", "Option 2", "Option 3"])
combobox.set("Default Option")
combobox.bind("<<ComboboxSelected>>", validate_selection)
combobox.pack()

# 创建按钮，用于将选择添加到列表
add_button = tk.Button(window, text="Add to List", command=add_to_list)
add_button.pack()

# 创建空的列表，用于存储正确的选择
correct_selections = []

# 运行窗口主循环
window.mainloop()