อยากทราบโค๊ด PHP ตรวจสอบ username และ password โดยผ่านทาง Active Directory ของ windows

<?PHP
$ldapbind = ldap_bind($ds,$user,$pass );  
$ldap_url = 'google.co.th';
$ldap_domain = 'co.th';
$ldap_dn = "dc=co,dc=th";

$ds = ldap_connect( $ldap_url );
ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);

$username = "tester";
//must always check that password length > 0
$password = "123456"; 

// now try a real login
$login = ldap_bind( $ds, "$username@$ldap_domain", $password ); 

try{
$attributes = array("displayname", "mail","department","title","physicaldeliveryofficename","company","telephonenumber");
$filter = "(&(objectCategory=person)(sAMAccountName=$username))";
$result = ldap_search($ds, $ldap_dn, $filter, $attributes);
$entries = ldap_get_entries($ds, $result);
if($entries["count"] > 0){
	for($x=0;$x<=count($attributes);$x++){
echo $attributes[$x].":".$entries[0][$attributes[$x]][0]."<br/>";
		}
	}
}
catch(Exception $e){
ldap_unbind($ds);
return;
}
ldap_unbind($ds);

?>