Sesiones

[bichomen]

Vale e autentificado al usuario haciendole introducir su nombre y contraseña y automaticamente le e metido

session_start();
session_register('s_usuario');
$s_usuario = $usuario;

y me da toda esta serie de fallos:

Warning: Cannot send session cookie - headers already sent by (output started at C:\apache 2\Apache2\htdocs\autentificacion.php:6) in C:\apache 2\Apache2\htdocs\autentificacion.php on line 76

Warning: Cannot send session cache limiter - headers already sent (output started at C:\apache 2\Apache2\htdocs\autentificacion.php:6) in C:\apache 2\Apache2\htdocs\autentificacion.php on line 76

Warning: open(/tmp\sess_d5846c8e79f8bdd57b6f71b30285ba21, O_RDWR) failed: m (2) in C:\apache 2\Apache2\htdocs\autentificacion.php on line 76

Warning: open(/tmp\sess_d5846c8e79f8bdd57b6f71b30285ba21, O_RDWR) failed: m (2) in Unknown on line 0

Warning: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0