Basic Web Hacking 18

This is about Basic Web Hacking 18 :

I read all the SQL injection tutorials in this site and all the posts in the forum concerning Basic Web Hacking 18. I googled some articles about b**SQLI. The common point in all these articles is that some characters are injected to see if the site is vulnerable or not . For example like:

?id=2 and 1=2 ?id=2 and 1=1

?id=2'

?id=2"

I tried many combinations to get the vulnerability , like in the above four examples, but I did not succeed : it only says "invalid article"

So I would like to know what I am missing . Any help would be appreciated

thanks

You already know it's vulnerable, move on to the next step and try to exploit it.

Ignore the part about it being blind, and follow the steps used in 'normal' error based sql injection .

it only says "invalid article"

There's a reason for that.