Username after using Facebook connect

How to get blank username after using Facebook connect.

Because during sign up with fb connect first name is retrieved as username. So user is skipping and not looking username.

Please could you describe in details how to reproduce the issue on demo.boonex.com ?

In demo.boonex.com, when I sign up in fb connect it is directly going to the profile. 

But in our site it will come back to the page fetching email id and first name as username.

So What I need is the username should not be fetched, I want it blank. The user should give his username.

Username can't be blank, so it's filled in with the possible available info. 

When Facebook connect redirect to member page, profile photo is fetching but redirect to join page photo is not fetching.

That's correct, photo isn't set when user is redirected to join form.