using urllib, urllib2 ,mechanize to access password protected site

[comeshopcheap]

Hi

I am using this script to access doba.com (I need to download some
files) but I keep on being sent back to the login page not the user
home page. Any help. I think I may need to use a post method and
opener is using a get method

Thanks

import mechanize
cookies = mechanize.CookieJar()
# build_opener() adds standard handlers (such as HTTPHandler and
# HTTPCookieProcessor) by default.  The cookie processor we supply
# will replace the default one.
opener =
mechanize.build_opener(mechanize.HTTPCookieProcessor(cookies))
opener.addheaders = [("User-agent", "Mozilla/5.0 (Windows; U; Windows
NT 5.1; en-US; rv:1.8.1.4) Gecko/20070515 Firefox/2.0.0.4"), ]
data="username=user&password=pw"
#r = opener.open("http://comeshopcheap.com/")  # GET
r = opener.open("https://www.doba.com/members/login.php", data)  # POST