problema database

[Werwolfe]

Ho risolto facendo cosi

$user_sql = "SELECT * FROM paziente_docware WHERE username='". $_POST['username']."'";
        $user_query = @mysql_query($user_sql);
                $user_result = @mysql_fetch_array($user_query);
        
        if(@mysql_num_rows($user_query) > 0)
        {
            echo "<script>";
                                    echo "alert('Nickname  presente nel database');";
                                    echo "</script>";
}  else {