[TYPO3] Keep login from different domains

[Andreas Wengrzik]

Hey list!

I´ve a typo3 4.0 installation and three domains...

The fact is if an user logs in from http:// www.domain1.com
he can do what he wants - if this user gets a link to 
http://domain1.com/whatever
he has to log in again - same if the link pints to 
http://www.domain2.com or http://domain2.com.

The Domains have the same documentroot so if i call them in the browser 
i get everytime the same page.

Any ideas?
Can i handle/solve this with typo3??

Thanks a lot!

-andreas w.