I have a problem sending data via http post  Gehe zur Blinded by the light Challenge

Following python code(2.7.5) is expected to show "Welcome back, user." But it shows "Your password is wrong," (This code does not contain the solution related to this challenge)
import re
import urllib
import urllib2


url = 'http://www.wechall.net/challenge/blind_light/index.php'
headers = { 'Cookie' : 'WC=~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'}

values = {'inject' : "' or 1=1#"}
data = urllib.urlencode(values)
req = urllib2.Request(url, data, headers)
response = urllib2.urlopen(req)
html = response.read()
print html

if re.findall("Welcome back, user.",html):
print "success",
else:
print "fail",
I tested this code with my testing website, and it worked well. But in wechall.net it didn't work as expected. Just sending one apostrophe or %27 through this code didn't show 'Database error'. What's the problem?

Maybe you need to add "Content-Type: application/x-www-form-urlencoded" header field?

I tried, but it didn't work.

I solved the problem, I should have sent 2 data, {'inject' : "Inject", 'injection' : "~~query~~"}