Non www. URL
 

I have a board that can be accessed with both www.zikihideout.com and zikihideout.com.I want the logins to work with both domains.How to achieve that?Thanks in advance

It's not what you're asking for, but you should force it to be one or the other using .htaccess. Not doing so hugely weakens your search engine concentration and generally confuses people. Not to mention throwing up the odd technical problem like this.

both aadresses would use cookies too, so a person logged into www.zikihideout.com may not be logged in from zikihideout.com they would have to input there username and password again to store a cookie.

htaccess or php redirect would be better and force just one.