var objType = null;
var objModel = null;
var objDEngine = null;
var objVehicle = null;

function GetVehicle()
{
	var vParams = [['get', '1']];
	var objAJAXRequest = new AJAXRequest('./domestic.php', 2, vParams, 'VehicleFinished');

	if(!objAJAXRequest) VehicleFinished(0);
}

function GetDEngine()
{
	ResetDEngine();

	if(objVehicle.value=='') return;
	
	var vParams = [['get', '2'], [objVehicle.id, objVehicle.value]];
	var objAJAXRequest = new AJAXRequest('./domestic.php', 2, vParams, 'DEngineFinished');

	if(!objAJAXRequest) DEngineFinished(0);
}

function GetModel()
{
	ResetModel();
	
	if(objDEngine.value=='') return;

	var vParams = [['get', '3'], [objVehicle.id, objVehicle.value], [objDEngine.id, objDEngine.value]];
	var objAJAXRequest = new AJAXRequest('./domestic.php', 2, vParams, 'ModelFinished');

	if(!objAJAXRequest) ModelFinished(0);
}

function VehicleFinished()
{
	if(arguments[0]) return;

	var vResult = arguments[1];
	var vVehicles = vResult.getElementsByTagName('VEHICLES')[0].getElementsByTagName('ITEM');

	while(objVehicle.options.length!=1) objVehicle.remove(1);

	for(var i=0; i<vVehicles.length; i++)
	{
		var opt = document.createElement('OPTION');
		opt.text = vVehicles[i].firstChild.nodeValue;
		opt.value = vVehicles[i].getAttribute('sheet');
		objVehicle.options.add(opt);
	}
	
	objVehicle.refresh(); objVehicle.selectedIndex = 0;
}

function DEngineFinished()
{
	if(arguments[0]) return;

	var vResult = arguments[1];
	var vEngines = vResult.getElementsByTagName('ENGINES')[0].getElementsByTagName('ITEM');

	ResetDEngine();
	
	for(var i=0; i<vEngines.length; i++)
	{
		var opt = document.createElement('OPTION');
		opt.text = vEngines[i].firstChild.nodeValue;
		opt.value = opt.text;
		objDEngine.options.add(opt);
	}
	
	objDEngine.refresh(); objDEngine.selectedIndex = 0;
}

function ModelFinished()
{
	if(arguments[0]) return;

	var vResult = arguments[1];
	var vModels = vResult.getElementsByTagName('MODELS')[0].getElementsByTagName('ITEM');

	ResetModel();

	for(var i=0; i<vModels.length; i++)
	{
		var opt = document.createElement('OPTION');
		opt.text = vModels[i].firstChild.nodeValue;
		opt.value = opt.text;
		objModel.options.add(opt);
	}
	
	objModel.refresh(); objModel.selectedIndex = 0;
}

function ResetDEngine()
{
	while(objDEngine.options.length!=0) objDEngine.remove(0);
	while(objModel.options.length!=0) objModel.remove(0);

	var opt = document.createElement('OPTION');
	if(objVehicle.value=='') opt.text = 'Select Vehicle First...';
	else opt.text = 'Select...'; opt.value = '';
	objDEngine.options.add(opt);

	ResetModel();
}

function ResetModel()
{
	while(objModel.options.length!=0) objModel.remove(0);

	var opt = document.createElement('OPTION');
	if(objDEngine.value=='') opt.text = 'Select Engine First...';
	else opt.text = 'Select...'; opt.value = '';
	objModel.options.add(opt);
}

function initializeD()
{
	objType = document.getElementById('cmbType');
	objModel = document.getElementById('cmbModel');
	objDEngine = document.getElementById('cmbDEngine');
	objVehicle = document.getElementById('cmbVehicle');
	
	GetVehicle();
}

if(window.attachEvent) window.attachEvent('onload', initializeD);
else window.addEventListener('load', initializeD, false);