from Tkinter import *

root = Tk()

x = 0

w = Label(root, text="Hello, world!")
w.pack()

def callback():
	global x
	x = x + 10
	w.config(text = "Score = "+ str(x))

button = Button(root, text="QUIT", fg="red", command=root.quit)
button.pack(side=LEFT)

work = Button(root, text="Go!", fg="red", command=callback)
work.pack(side=RIGHT)

root.mainloop()