login da database e + variabile.

[luik]

scusate, ma ho postato il codice vecchio , per ora uso questo:

come mai se metto
if ( $_POST['username'] != '' && $_POST['password'] != '' && $_POST["pin"] == "" )
{
}

non fai il controllo ?.

grazie.

<?php
session_start();
require_once(dirname(__FILE__) . "/../include.php");



    if (array_key_exists('_submit_check', $_POST))
    {
        if ( $_POST['username'] != '' && $_POST['password'] != '' && $_POST["pin"] == "" )
        {
            $query = mysql_query ( 'SELECT ID, Username, Active FROM users WHERE Username = "' . mysql_codifica ( $_POST['username'] ) . '" AND Password = "' . mysql_codifica ( md5($_POST['password'] ) ) . '"' );
            
            if ( mysql_num_rows($query) == 1 )
            {
                $row = mysql_fetch_assoc ( $query );
                if ( $row['Active'] == 1 )
                {
                    $_SESSION['user_id'] = $row['ID'];
                    $_SESSION['username'] = $row["Username"];
                    $_SESSION['logged_in'] = TRUE;
                    $msg = "Attendere prego ";
                    redirect("default/",5);
                }
                elseif ( $row['Active'] == 0 ) {
                    $error = 'Your membership was not activated. Please open the email that we sent and click on the activation link';
                }
                elseif ( $row['Active'] == 2 ) {
                    $error = 'You are suspended!';
                }
            }
            else {        
                $error = 'Login failed!';        
            }
        }
        else {
            $error = 'Please use both your username and password to access your account';
        }
    }
?>    <p class="text">Login</p>
    <div id="log">
<?php if(isset($error)){ echo '            <p class="error">' . $error . '</p>' . "\n";}?>
<?php    if ( isset ( $msg ) )    { echo '            <p class="msg">' . $msg . '</p>' . "\n";    } else {//if we have a mesage we don't need this form again.?>
    
    </div>

        <form class="form" action="<?php echo $_SERVER['PHP_SELF']?>" method="post">

            <input type="hidden" name="_submit_check" value="1"/> 
        
            <div style="margin-top:12px; margin-bottom:10px">
                [img]images/username.gif[/img]
                <input class="input" type="text" name="username" id="username" size="25" maxlength="40" value="" />
            </div>
            <div style="margin-bottom:6px">
                [img]images/password.gif[/img]
                <input class="input" type="password" name="password" id="password" size="25" maxlength="32" />

            </div>
                <div style="margin-bottom:6px">
                Pin
                <input class="input" type="password" name="pin" id="pin" size="25" maxlength="32" />

            </div>
            <input type="submit" name="Login" value="Login"   alt="submit" title="submit" />
            <br class="clear" />
            [url="register.php"]Register[/url]
            
        </form>
        <?php } ?>
        
    <?php mysql_close($db); ?>