Client side network programming

[Roysun_rohit]

I am interested in making a search engine which takes web sites
iteratively, and downloads the web page or has to perform some search
across the web pages.
I am unsucessful to do so. My machine works through a proxy server and the
internet connection is through 24 hour lease line. when ever i try the
code it gives :

Traceback (innermost last):
  File "http-getfile-urllib2.py", line 19, in ?
    urllib.urlretrieve(remoteaddr, localname)
  File "/usr/lib/python1.5/urllib.py", line 66, in urlretrieve
    return _urlopener.retrieve(url, filename, reporthook)
  File "/usr/lib/python1.5/urllib.py", line 186, in retrieve
    fp = self.open(url)
  File "/usr/lib/python1.5/urllib.py", line 159, in open
    return getattr(self, name)(url)
  File "/usr/lib/python1.5/urllib.py", line 260, in open_http
    h = httplib.HTTP(host)
  File "/usr/lib/python1.5/httplib.py", line 53, in __init__
    if host: self.connect(host, port)
  File "/usr/lib/python1.5/httplib.py", line 81, in connect
    self.sock.connect(host, port)
IOError: [Errno socket error] (101, 'Network is unreachable')
============================================================
The code is like this:-
#!/usr/bin/env python
import os, sys, urllib, urlparse, socket
showlines = 6
try:
    servername, filename = sys.argv[1:3]
except:
    servername, filename = 'www.igib.res.in', '/sarsanalysis.html'
    
remoteaddr = 'http://%s%s' % (servername, filename)
if len(sys.argv) == 4:
   localname = sys.argv[3]
else:
   (scheme, server, path, parms, query, frag) =
urlparse.urlparse(remoteaddr)
   localname = os.path.split(path)[1]
   
print remoteaddr, localname
urllib.urlretrieve(remoteaddr, localname)
remotedata = open(localname).readlines()
for line in remotedata[:showlines]: print line,
============================================================
I am new to the internet programming as well as python. please guide me,
how to solve this one.