Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/....../........net/....../idare/giriskontrol.php:1) in /home/....../........net/....../idare/giriskontrol.php on line 2

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/....../........net/....../idare/giriskontrol.php:1) in /home/....../........net/....../idare/giriskontrol.php on line 2

Warning: Cannot modify header information - headers already sent by (output started at /home/....../........net/....../idare/giriskontrol.php:1) in /home/....../........net/....../idare/giriskontrol.php on line 30


2 sırada bu yazıyor session_start();
30 sırada da echo header('location:index.php');


bu şekilde hata alıyorum arkadaşlar yardımcı olabilecek var mı?