if ($_GET['task'] == "register") {
    $user = zastiti($_GET['user']);
    $mail = zastiti($_GET['mail']);
    $pass = zastiti($_GET['pass']);
    $pass1 = zastiti($_GET['pass1']);

    $proverausera = mysql_query("SELECT * FROM users WHERE username='$user'") or die(mysql_error());
    if (mysql_num_rows($proverausera) > 0)
    die("5");

    if (empty($username)){
    die("1");
    }
    elseif (empty($password)){
    die("2");
    }
    elseif (!eregi ( "^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email )){
    die("3");
    }
    elseif($pass != $pass1)
    die("4");
    else{
    $kriptovan = md5($pass);
    $tajm = time();
    $potvrda = md5($tajm);
    $insert = "INSERT INTO users (username, password, mail, potvrda, aktivnost, registracija)
    VALUES ('$user','$kriptovan','$mail','$potvrda','$tajm','$tajm')";
    die("0");
    }

}