Forum add domain alias to forum

[محروم.كوم]

Hi
i want to add domain alias for my forum. i add my domain alias in plesk control panel and domain work properly. but when i go to that domain it's redirect to forum original domain.
i change my forum url in VB setting. but i want to have both of them or even more domain.

my domain is tvshow.ir and my forum install on forum.tvshow.ir
when i add another alias for example tvshow2.ir and go to forum.tvshow2.ir it's redirected to forum.tvshow.ir !!! how do i can solve this problem ? __DEFINE_LIKE_SHARE__