PHP - MYSQL CONTROL TRANSACTION

<?php
    // source code PHP MySQL Control Transaction
    // trans.php

/*
DATABASE & TABLE
create database test;
use test;

CREATE TABLE trans
(
id int not null auto_increment,
item varchar(30) not null,
quantity varchar(10) not null,
primary key(id)
);

INSERT INTO trans (id,item,quantity) VALUES (NULL,'Computer','5');
*/

function begin() { @mysql_query("BEGIN"); }
function commit() { @mysql_query("COMMIT"); }
function rollback() { @mysql_query("ROLLBACK"); }

@mysql_connect("localhost","root", "--ipv6--") or die(mysql_error());
@mysql_select_db("test") or die(mysql_error());

$query = "INSERT INTO trans (id,item,quantity) values (null,'Baseball',4)";
begin(); // transaction dimulai
$result = @mysql_query($query);
if(!$result)
{
rollback(); // transaction rolls back
echo "you rolled back";
exit;
}
else
{
commit(); // transaction berhasil di commit
echo "your insertion was successful";
}
?>