import Tkinter as tk
import tkMessageBox
def showInformationBox():
    tkMessageBox.showinfo("Info","Nice Done")
def showOkCancelBox():
    tkMessageBox.askokcancel("okCancel","Remove all System Files?")
def showWarningBox():
    tkMessageBox.showwarning("warning","This is a warning")
def showErrorBox():
    tkMessageBox.showerror("error","Critical System Error #00000")
root = tk.Tk()
root.title("Computer Science")
message = tk.Label( root, text = "Introduction to Computer Science" )
message.pack()
message2 = tk.Label( root, text = "This is my first program" )
message2.pack()
buttonA = tk.Button( root, text = "Click here for Information", command = showInformationBox)
buttonA.pack()
buttonB = tk.Button( root, text = "Click here for Verification", command = showOkCancelBox)
buttonB.pack()
buttonC = tk.Button( root, text = "Click here for Warning", command = showWarningBox)
buttonC.pack()
buttonD = tk.Button( root, text = "Click here for Error Message", command = showErrorBox)
buttonD.pack()
root.mainloop()