import sys
import pygame
import time

pygame.init()

width = 500
height = 400
speed = [2, 2]
black = 0, 0, 0
screen = pygame.display.set_mode((width, height))
ball = pygame.image.load("intro_ball.gif")
ballrect = ball.get_rect()

while True:
	for event in pygame.event.get():
		if event.type == pygame.QUIT:
			sys.exit()

	ballrect = ballrect.move(speed)
	if ballrect.left < 0 or ballrect.right > width:
		speed[0] = -speed[0]
	if ballrect.top < 0 or ballrect.bottom > height:
		speed[1] = -speed[1]

	screen.fill(black)
	screen.blit(ball, ballrect)
	pygame.display.flip()
	time.sleep(.05)

