session_star() problem

Ok I am starting on small web site and using PHP 4 on Apache with FreeBSD 4.4 as the OS. I need to use sessions to pass some info around between pages but when I use session_start() I get the error msg below. Warning: Cannot send session cookie - headers already sent by (output started at /usr/home/gate/public_html/product_list.php:8) in /usr/home/gate/public_html/product_list.php on line 9 Warning: Cannot send session cache limiter - headers already sent (output started at /usr/home/gate/public_html/product_list.php:8) in /usr/home/gate/public_html/product_list.php on line 9 I get this msg if it is the only thing in the php script as well as if it is in an actually script that I am using. Maybe I don't php set up right or something else.Could some one please put me in the right direction. Greg please reply to my email as well as the newsgroup