// data - массив с данными вида data[id_model] = название модели

$data = Orders::getModelsByMark(Database::getInstance(), $id_marki);

header('Content-type: application/json; charset=utf-8');
echo json_encode($data);

// для вставки данных в селект с моделями
function AddSelectOption(selectObj, text, value, isSelected)
{
if (selectObj != null && selectObj.options != null)
{
selectObj.options[selectObj.options.length] =
new Option(text, value, false, isSelected);
}
}
// подчистка селекта с моделями и заполнение его данными
function ShowModels(value)
{
	new Ajax.Request('/ajax/models/',
	{
	method:'get',
	parameters: { id_marki: value },
	onSuccess: function(transport)
	{
	$('id_model').options.length =  0 ;

// вот тут и есть вопрос... как лучше пробежаться по transport.responseJSON, типа foreach в php, чтобы заполнить селект с моделями через AddSelectOption
// почему-то через transport.responseJSON.lenght не получается...

//	AddSelectOption($('id_model'), "модель", "id_модели", true);
//	AddSelectOption($('id_model'), transport.responseJSON['1'], "1", true);

	}
	}
	);
}

{ 668 :"100 NX", 669 :"200 SX", 670 :"280 ZX", 671 :"300 ZX", 672 :"350 Z", 673 :"Almera", 674 :"Altima", 675 :"Armada", 676 :"Avenir", 677 :"Bassara", 678 :"Bluebird", 679 :"Cedric", 680 :"Cefiro", 681 :"Cherry", 682 :"Cima", 683 :"Crew", 684 :"Cube", 685 :"Datsun", 686 :"Elgrand", 687 :"Gloria", 688 :"Largo", 689 :"Laurel", 690 :"Leopard", 691 :"Liberty", 692 :"Lucino", 693 :"March", 694 :"Maxima", 695 :"Micra", 696 :"Moco", 697 :"Murano", 698 :"Navara", 699 :"Note", 700 :"Pathfinder", 701 :"Patrol", 702 :"PickUp", 703 :"Prairie", 704 :"Presage", 705 :"Presea", 706 :"President", 707 :"Primastar", 708 :"Primera", 709 :"Pulsar", 710 :"Qashqai", 711 :"Quest", 712 :"R Nessa", 713 :"Rasheen", 714 :"Safari", 715 :"Sentra", 716 :"Serena", 717 :"Silvia", 718 :"Skyline", 719 :"Stagea", 720 :"Stanza", 721 :"Sunny", 722 :"Teana", 723 :"Terrano", 724 :"Tiida", 725 :"Tino", 726 :"Urvan", 727 :"Vanette", 728 :"Wingroad", 729 :"X-Terra", 730 :"X-Trail"}

[{"id":"668","title":"100 NX"},{"id":"669","title":"200 SX"},{"id":"670","title":"280 ZX"},{"id":"671","title":"300 ZX"},{"id":"672","title":"350 Z"},{"id":"673","title":"Almera"},{"id":"674","title":"Altima"},{"id":"675","title":"Armada"},{"id":"676","title":"Avenir"},{"id":"677","title":"Bassara"},{"id":"678","title":"Bluebird"},{"id":"679","title":"Cedric"},{"id":"680","title":"Cefiro"},{"id":"681","title":"Cherry"},{"id":"682","title":"Cima"},{"id":"683","title":"Crew"},{"id":"684","title":"Cube"},{"id":"685","title":"Datsun"},{"id":"686","title":"Elgrand"},{"id":"687","title":"Gloria"},{"id":"688","title":"Largo"},{"id":"689","title":"Laurel"},{"id":"690","title":"Leopard"},{"id":"691","title":"Liberty"},{"id":"692","title":"Lucino"},{"id":"693","title":"March"},{"id":"694","title":"Maxima"},{"id":"695","title":"Micra"},{"id":"696","title":"Moco"},{"id":"697","title":"Murano"},{"id":"698","title":"Navara"},{"id":"699","title":"Note"},{"id":"700","title":"Pathfinder"},{"id":"701","title":"Patrol"},{"id":"702","title":"PickUp"},{"id":"703","title":"Prairie"},{"id":"704","title":"Presage"},{"id":"705","title":"Presea"},{"id":"706","title":"President"},{"id":"707","title":"Primastar"},{"id":"708","title":"Primera"},{"id":"709","title":"Pulsar"},{"id":"710","title":"Qashqai"},{"id":"711","title":"Quest"},{"id":"712","title":"R Nessa"},{"id":"713","title":"Rasheen"},{"id":"714","title":"Safari"},{"id":"715","title":"Sentra"},{"id":"716","title":"Serena"},{"id":"717","title":"Silvia"},{"id":"718","title":"Skyline"},{"id":"719","title":"Stagea"},{"id":"720","title":"Stanza"},{"id":"721","title":"Sunny"},{"id":"722","title":"Teana"},{"id":"723","title":"Terrano"},{"id":"724","title":"Tiida"},{"id":"725","title":"Tino"},{"id":"726","title":"Urvan"},{"id":"727","title":"Vanette"},{"id":"728","title":"Wingroad"},{"id":"729","title":"X-Terra"},{"id":"730","title":"X-Trail"}]