Warning: Cannot modify header information

[eburlea]

I get an error and I cannot figure out what is the problem.

Error:

Warning: Cannot modify header information - headers already sent by (output started at z:\home\localhost\www\soccerstatistics\admin\new_team.php:1) in z:\home\localhost\www\soccerstatistics\admin\lock.php on line 6

1. <?php
2. include("blocks/db.php");
3. if (!isset($_SERVER['PHP_AUTH_USER']))
4. {
5. Header ("WWW-Authenticate: Basic realm=\"Admin Page\"");
6. Header ("HTTP/1.0 401 Unauthorized");
7. exit();
8. }
9. 
   11.else {
10. if (!get_magic_quotes_gpc()) {
11. $_SERVER['PHP_AUTH_USER'] = mysql_escape_string($_SERVER ['PHP_AUTH_USER']);
12. $_SERVER['PHP_AUTH_PW'] = mysql_escape_string($_SERVER['PHP_AUTH_PW']);
13. }
14. $query = "SELECT pass FROM userlist WHERE user='".$_SERVER['PHP_AUTH_USER']."'";
15. $lst = @mysql_query($query);
16. if (!$lst)
17. {
18. Header ("WWW-Authenticate: Basic realm=\"Admin Page\"");
19. Header ("HTTP/1.0 401 Unauthorized");
20. exit();
21. }
22. if (mysql_num_rows($lst) == 0)
23. {
24. Header ("WWW-Authenticate: Basic realm=\"Admin Page\"");
25. Header ("HTTP/1.0 401 Unauthorized");
26. exit();
27. }
28. $pass = @mysql_fetch_array($lst);
29. if ($_SERVER['PHP_AUTH_PW']!= $pass['pass'])
30. {
31. Header ("WWW-Authenticate: Basic realm=\"Admin Page\"");
32. Header ("HTTP/1.0 401 Unauthorized");
33. exit();
34. }
    41.}
    42.?>

Please advise...