[RESOLVED] Help! Doesn't work! And it's some important homework

[sveegaard]

Hi,
This code does not update the user's informations stored in a database:

<?php
include('config.php');
// connect to the mysql database server.
mysql_connect ($dbhost, $dbusername, $dbuserpass);
mysql_select_db($dbname) or die("Cannot select database");

$nyt_pass = md5($_POST['new_password']);
$b_nyt_pass = md5($_POST['confirm_new_password']);
$email = $_POST['email'];
$password = md5($_POST['password']);
$username = $_SESSION['s_username'];

if($nyt_pass==""|$b_nyt_pass==""|$email==""){
    echo '
    <script language="javascript" type="text/javascript">
    alert("Du skal mindst have udfyldt e-mail!");
    top.location.replace("oplysninger.php");
    </script>';
}

if($nyt_pass==""|$b_nyt_pass==""){
    $query = mysql_query("SELECT * FROM users WHERE username = '$username'") or die(mysql_error()); 
    $row = mysql_fetch_array($query);
    if ($password=="") {
        echo '
        <script language="javascript" type="text/javascript">
        alert("Kodeordet er ikke indtastet!");
        top.location.replace("oplysninger.php");
        </script>';
        }
    if($password!=$row['password']){
        echo '
        <script language="javascript" type="text/javascript">
        alert("Kodeordet er ikke korrekt!");
        top.location.replace("oplysninger.php");
        </script>';
    }else{
        mysql_query("UPDATE users SET `email` = '$email' WHERE `username` = '$username'") or die(mysql_error());
        echo '<script language="javascript" type="text/javascript">
        alert("Dine oplysninger er blevet ændret!");
        top.location.replace("index.php");
        </script>';
        }
    }
    

if($nyt_pass!=$b_nyt_pass){
    echo '<script language="javascript" type="text/javascript">
    alert("Indtastingsfejl i dit nye kodeord!");
    top.location.replace("oplysninger.php");
    </script>';
    }
    
header("Location: oplysninger.php");
?>

It's kinda messy but I hope you can interpret it