right place to start a session?

Here's my code: <html> <body> <?php //trying to start a session right here for the usr and pwd variables session_start(); session_register("usr", "pwd"); if (isset($login)): ?> <FORM ACTION='<?php echo($PHP_SELF); ?> etc., etc where the usr enters their usrname and pwd but I get the following errors: Warning: Cannot send session cookie - headers already sent by (output started at c:\program files\apache group\apache\htdocs\newsadmin\news.php:3) in c:\program files\apache group\apache\htdocs\newsadmin\news.php on line 5 Warning: Cannot send session cache limiter - headers already sent (output started at c:\program files\apache group\apache\htdocs\newsadmin\news.php:3) in c:\program files\apache group\apache\htdocs\newsadmin\news.php on line 5 Have tried moving the session to the next part of the script after the form posts to self with no success. I would like to "keep" the usr and pwd variables for use later since it involves multiple queries to MySQL, right now I have to have the information entered "AGAIN!" and I know that is a pain for users. Please help me out - there are several <form>'s in the script using $PHP_SELF and it seems sessions is the way to go. I'm in need of a good samaritan here... Thanks! -Kirk