button onclick message box in python tkinter

1import tkinter as tk
2from tkinter import messagebox
3
4root= tk.Tk()
5
6canvas1 = tk.Canvas(root, width = 300, height = 300)
7canvas1.pack()
8
9def ExitApplication():
10    MsgBox = tk.messagebox.askquestion ('Exit Application','Are you sure you want to exit the application',icon = 'warning')
11    if MsgBox == 'yes':
12       root.destroy()
13    else:
14        tk.messagebox.showinfo('Return','You will now return to the application screen')
15        
16button1 = tk.Button (root, text='Exit Application',command=ExitApplication,bg='brown',fg='white')
17canvas1.create_window(150, 150, window=button1)
18  
19root.mainloop()
20

1import tkinter.messagebox
2def onClick():
3    tkinter.messagebox.showinfo("Title goes here","Message goes here")
4root = tkinter.Tk()
5button = tkinter.Button(root,text = "Click Me", command = onClick)
6button.pack()
7root.mainloop()
8