#coding: utf8from Tkinter import *def reg():    s1 = e1.get()    s2 = e2.get()    t1 = len(s1)    t2 = len(s2)    if s1 == "111" and s2 == "222":        c["text"] = "login success."    else:        c["text"] = "user or password is wrong."        e1.delete(0, t1)        e2.delete(0, t2)root = Tk()root.wm_title("hello")l1 = Label(root, text="username: ")l1.grid(row=0, column=0, sticky=W)e1 = Entry(root)e1.grid(row=0, column=1, sticky=E)l2 = Label(root, text="password: ")l2.grid(row=1, column=0, sticky=W)e2 = Entry(root)e2['show'] = "*"e2.grid(row=1, column=1, sticky=E)b = Button(root, text="Login", command=reg)b.grid(row=2, column=1, sticky=E)c = Label(root, text="")c.grid(row=3)root.mainloop()