Can an inactive twitter username be removed and taken by another username on request?

Is it possible that a username which i am unsure if it is inactive or active br removed and given to me by twitter?

What i want is that can i take the username - "adnan" and swap it for my existing username - "adnan_chowdhury"?

Apparently it can be done as said in this website- http://thenextweb.com/2009/01/08/how-...

But i tried it and it did not work.

Please help!!!

Thanks in advance...