errore nella query

Allora, io ho questi 2 files:

registration.php

<?php
    //Start session
    session_start();
    
    //Include database connection details
    require_once('config.php');
    
    //Array to store validation errors
    $errmsg_arr = array();
    
    //Validation error flag
    $errflag = false;
    
    //Connect to mysql server
    $link = mysql_connect($host, $username, $password);
    if(!$link) {
        die('Failed to connect to server: ' . mysql_error());
    }
    
    //Select database
    $db = mysql_select_db($db_name, $link);
    if(!$db) {
        die("Unable to select database");
    }
    
    //Function to sanitize values received from the form. Prevents SQL injection
    function clean($str) {
        $str = @trim($str);
        if(get_magic_quotes_gpc()) {
            $str = stripslashes($str);
        }
        return mysql_real_escape_string($str);
    }
    
    //Sanitize the POST values
    $fname = clean($_POST['fname']);
    $lname = clean($_POST['lname']);
    $login = clean($_POST['login']);
    $password = clean($_POST['password']);
    $cpassword = clean($_POST['cpassword']);
    
    //Input Validations
    if($fname == 'bill') {
        $errmsg_arr[] = 'tu non ti chiami bill gates';
        $errflag = true;
    }
    if($lname == 'gates') {
        $errmsg_arr[] = 'sisi e io sono tua nonna XDDDD';
        $errflag = true;
    }
    if($login == '') {
        $errmsg_arr[] = 'Non hai inserito la tua login id';
        $errflag = true;
    }
    if($password == '') {
        $errmsg_arr[] = 'Non hai inserito la tua password';
        $errflag = true;
    }
    if($cpassword == '') {
        $errmsg_arr[] = 'Non hai la conferma password';
        $errflag = true;
    }
    if( strcmp($password, $cpassword) != 0 ) {
        $errmsg_arr[] = 'Le password non corrispondono';
        $errflag = true;
    }
    
    //Check for duplicate login ID
    if($login != '') {
        $qry = "SELECT * FROM members WHERE login='$login'";
        $result = mysql_query($qry);
        if($result) {
            if(mysql_num_rows($result) > 0) {
                $errmsg_arr[] = 'Username giá esistente';
                $errflag = true;
            }
            @mysql_free_result($result);
        }
        else {
            die("Query failed");
        }
    }
    
    //If there are input validations, redirect back to the registration form
    if($errflag) {
        $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
        session_write_close();
        header("location: register-form.php");
        exit();
    }

    //Create INSERT query
    $qry = "INSERT INTO members(firstname, lastname, login, passwd) VALUES('$fname','$lname','$login','".md5($_POST['password'])."')";
    $result = @mysql_query($qry);
    
    //Check whether the query was successful or not
    if($result) {
        echo "Registrazione avvenuta con successo";
        exit();
    }else {
        die("Query failed");
    }
?>

e config.php

<?php
$host="localhost"; // Host name
$username="browsergamemio"; // Mysql username
$password=""; // Mysql password
$db_name="my_browsergamemio"; // Database name
$tbl_name="members"; // Table name

// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");
?>

Eppure se tento di registrarmi mi dà un "Query failed"! Dove sbaglio?

Prova a vedere che cosa restituisce modificando questa parte del file registration.php:

    if($result) {
        echo "Registrazione avvenuta con successo";
        exit();
    }else {
        die("Query failed");
    } 

In modo che visualizzi l'errore, così:

    if($result) {
        echo "Registrazione avvenuta con successo";
        exit();
    }else {
        die(mysql_error());
    }