trying to display user name

[T12]

im trying to display uesrs name that is loged in but i keep getting this message

Welcome
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/acblfayd/public_html/home.php:16) in /home/acblfayd/public_html/home.php on line 96
sean9355!