Cookie problem
 

www.domain.com
http://domain.com

Now the odd thing is if a member types in "www.domain.com" they are not logged in.
The reason is the script is all set for http://domain.com so there are no log in problems there but as soon as someone attempts to access via www.domain.com it states they are logged out.

So my question is what do I do?
Cookie settings are on default.