sessions and unicode!

Hi I'm designing a site with php that it has a login page. the login page uses sessions; when I save my document normally it works , an everything is ok , but when I save it as a UTF-8 document, it says : Warning: Cannot send session cache limiter - headers already sent (output started at ... what should I do to make a unicode login page that uses sessions? thanx _________________________________________________________________ Add photos to your e-mail with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail