Error en sesion

[skanabis]

porque me da este error en sesiones php?


Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at C:\AppServ\www\sentirmusica\log.php:8) in C:\AppServ\www\sentirmusica\log.php on line 9

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at C:\AppServ\www\sentirmusica\log.php:8) in C:\AppServ\www\sentirmusica\log.php on line 9



<?
session_start();


class login{

var $db_conexion;

function __construct($usr , $pass ){

$this -> connect_bd($usr , $pass );

}



function connect_bd($usr , $pass){

$this -> db_conexion=mysql_pconnect('localhost',$… ,$pass);
mysql_select_db('artistas');
if($db_conexion){

echo' No se pudo conectar a la base de datos intentelo mas tarde ';
exit;

}

else{

session_register("usuario");
$_SESSION["usuario"] = $usr;

session_register("password");
$_SESSION['password'] = $pass;

echo "se conecto correctamente";

}

}

}


$log = new login($_POST[usr] , $_POST[pass]);


?>