py打开网页报错！

我用下面一段话想打开一个网页，但是总是报错，程序如下：
import urllib                                       
sock = urllib.urlopen("http://www.sina.com/")

报错为：
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    sock = urllib.urlopen("http://www.sina.com/")
  File "C:\Python25\lib\urllib.py", line 82, in urlopen
    return opener.open(url)
  File "C:\Python25\lib\urllib.py", line 190, in open
    return getattr(self, name)(url)
  File "C:\Python25\lib\urllib.py", line 325, in open_http
    h.endheaders()
  File "C:\Python25\lib\httplib.py", line 856, in endheaders
    self._send_output()
  File "C:\Python25\lib\httplib.py", line 728, in _send_output
    self.send(msg)
  File "C:\Python25\lib\httplib.py", line 695, in send
    self.connect()
  File "C:\Python25\lib\httplib.py", line 679, in connect
    raise socket.error, msg
IOError: [Errno socket error] (10061, 'Connection refused')


请问高手这是什么问题啊！！！！

我这边试过了，没啥问题的哦，打开这个报错你再换下其他网址看看。