session_start

[regedit]

session_start

chi mi aiuta a risolvere questi errori?:(
Notice: Undefined index: username in y:\home\login\www\index.php on line **88
**Notice: Undefined index: username in y:\home\login\www\index.php on line 93

Warning: Cannot modify header information - headers already sent by (output started at y:\home\login\www\index.php:88) in y:\home\login\www\index.php on line **143

il codice è:
<?php

define('INCLUDE_CHECK',true);

require 'connect.php';
require 'functions.php';
// Those two files can be included only if INCLUDE_CHECK is defined

session_start();

session_name('tzLogin');
// Starting the session

session_set_cookie_params(27246060);
// Making the cookie live for 2 weeks

if(isset($_SESSION['id']) && !isset($_COOKIE['tzRemember']) && !isset($_SESSION['rememberMe']))
{
// If you are logged in, but you don't have the tzRemember cookie (browser restart)
// and you have not checked the rememberMe checkbox:

$_SESSION = array();
session_destroy();

// Destroy the session

}

if(isset($_GET['logoff']))
{
$_SESSION = array();
session_destroy();

header("Location: index.php");
exit;

}

if(isset($_POST['submit']) && $_POST['submit']=='Login')
{
// Checking whether the Login form has been submitted

$err = array();
// Will hold our errors


if(!$_POST['username'] || !$_POST['password'])
    $err[] = 'All the fields must be filled in!';

if(!count($err))
{
    $_POST['username'] = mysql_real_escape_string($_POST['username']);
    $_POST['password'] = mysql_real_escape_string($_POST['password']);
    $_POST['rememberMe'] = (int)$_POST['rememberMe'];
    
    // Escaping all input data

    $row = mysql_fetch_assoc(mysql_query("SELECT id,usr FROM tz_members WHERE usr='{$_POST['username']}' AND pass='".md5($_POST['password'])."'"));

    if($row['usr'])
    {
        // If everything is OK login
        
        $_SESSION['usr']=$row['usr'];
        $_SESSION['id'] = $row['id'];
        $_SESSION['rememberMe'] = $_POST['rememberMe'];
        
        // Store some data in the session
        
        setcookie('tzRemember',$_POST['rememberMe']);
    }
    else $err[]='Wrong username and/or password!';
}

if($err)
$_SESSION['msg']['login-err'] = implode('<br />',$err);
// Save the error messages in the session

header("Location: index.php");
exit;

}
else if(isset($_POST['submit']) && $_POST['submit']=='Register')
{
// If the Register form has been submitted

$err = array();

if(strlen($_POST['username'])<4 || strlen($_POST['username'])>32)
{
    $err[]='Your username must be between 3 and 32 characters!';
}

if(preg_match('/[^a-z0-9\-\_\.]+/i',$_POST['username']))
{
    $err[]='Your username contains invalid characters!';
}

if(!checkEmail($_POST['email']))
{
    $err[]='Your email is not valid!';
}

if(!count($err))
{
    // If there are no errors
    
    $pass = substr(md5($_SERVER['REMOTE_ADDR'].microtime().rand(1,100000)),0,6);
    // Generate a random password
    
    $_POST['email'] = mysql_real_escape_string($_POST['email']);
    $_POST['username'] = mysql_real_escape_string($_POST['username']);
    // Escape the input data
    
    
    mysql_query("    INSERT INTO tz_members(usr,pass,email,regIP,dt)
                    VALUES(
                    
                        '".$_POST['username']."',
                        '".md5($pass)."',
                        '".$_POST['email']."',
                        '".$_SERVER['REMOTE_ADDR']."',
                        NOW()
                        
                    )");
    
    if(mysql_affected_rows($link)==1)
    {
        send_mail(    '[email protected]',
                    $_POST['email'],
                    'Registration System Demo - Your New Password',
                    'Your password is: '.$pass);

        $_SESSION['msg']['reg-success']='We sent you an email with your new password!';
    }
    else $err[]='This username is already taken!';
}

if(count($err))
{
    $_SESSION['msg']['reg-err'] = implode('<br />',$err);
}    

header("Location: index.php");
exit;

}

$script = '';

if($_SESSION['msg'])
{
// The script below shows the sliding panel on page load

$script = '
<script type="text/javascript">

    $(function(){
    
        $("div#panel").show();
        $("#toggle a").toggle();
    });

</script>';

}
?>

**

[antoniog2]

Perchè fai riavviare il browser per settare il cookie?
L'utente potrebbe considerarla una operazione malevola da parte di un cracker. Ma è una tua scelta. Io mostrerei una popup che richiede i dati da inserire nel cookie, per esempio.
Forse fai eseguire session_destroy() prima di header("Location: index.php")

[antoniog2]

Per il cookie: ricorri al cookie di sessione incorporando SID nella tua istruzione e se non puoi utilizzare il cookie nella macchina dell'utente in quanto non presente.
Devi quindi usare $_COOKIE per verificare se tutti i valori che vuoi verificarne l'esiostenza nel cookie sulla macchina del tuo utente.
Vedi il manuale online di PHP.