def login_verify():
    db = sqlite3.connect("userfile.db")
    c = db.cursor()
    u_crypt = sha256_crypt.encrypt(username_verify.get())
    p_crypt = sha256_crypt.encrypt(password_verify.get())
    dbusername= "SELECT * from user WHERE username = '%s'"
    dbpassword = "SELECT * from user WHERE password = '%s'"
    if [(sha256_crypt.verify(dbusername, u_crypt)) == True] and [(sha256_crypt.verify(dbpassword, p_crypt)) == True]:
        ms.showinfo(title="Welcome", message=("You are Logged in"))
    elif [(sha256_crypt.verify(dbusername, u_crypt)) == True] and [(sha256_crypt.verify(dbpassword, p_crypt)) != True]:
        ms.showerror(title="ERROR", message=("Invalid Password!"))
        Label(login_screen, text="Login Failed", fg="red", font=("calibri", 11)).pack()
        Label.after(1000 , Label.destroy)
    elif [(sha256_crypt.verify(dbusername, u_crypt)) != True] and [(sha256_crypt.verify(dbpassword, p_crypt)) == True]:
        ms.showerror(title="ERROR", message=("Username does not exist!"))
        Label(login_screen, text="Login Failed", fg="red", font=("calibri", 11)).pack()
        Label.after(1000 , Label.destroy)
    else:
        ms.showerror(title="ERROR", message="Invalid Username or Password!")
        Label(login_screen, text="Login Failed", fg="red", font=("calibri", 11)).pack()
        Label.after(1000 , Label.destroy)