note 29941 added to faq.using

What happen with my code!!? I writed this code ... line1 session_start(); line2 If(!session_is_registered("count")) { line3 $count = 0; line4 session_register("count"); line5 } when I run this code,I found error... Warning: Cannot send session cookie - headers already sent by (output started at /home/myusername/myhome-www/product.php:4) on line 1 Warning: Cannot send session cache limiter - headers already sent (output started at /home/myusername/myhome-www/product.php:4) on line 1 when I cut out line1 code,I found same error but happen with line4 code is error.... I want to know meaning of those error....It's mean? -- http://www.php.net/manual/en/faq.using.php http://master.php.net/manage/user-notes.php?action=edit+29941 http://master.php.net/manage/user-notes.php?action=delete+29941 http://master.php.net/manage/user-notes.php?action=reject+29941