Please check the Member List to make sure the name doesn't exist already before making the request, it will save everyone some time if you don't request a name already registered.
If you don't want to browse the list just try going to this page (you must be logged in)
Code:
https://vborg.vbsupport.ru/member.php?username=birdoprey5
Change
birdoprey5 with the username you want to check, if you get a profile page, the name is taken.