Redirect non-WWW BHW to WWW, please

First of all, it's no bueno to allow access to both the non-WWW and WWW versions of a website, so you need to pick one or the other.

Also, it is nearly impossible to login on the non-WWW version (blackhatworld.com); it only works on http://www.blackhatworld.com

This may be because the non-WWW has a different structure than the WWW and cannot access PHP stored $_SESSION values.

Please fix this for the sake of canonical URLs and elimination of this technical glitch.