Event.observe(window, 'load', function() {
	$('make_id').disabled = false;
	Event.observe('make_id', 'change', function(evt) {
		new Ajax.Request('./ajax/getmodel.php', {
			method: 'post',
			parameters: { 'make_id': $('make_id').value },
			onSuccess: function(transport) {
				resetSelectToChooseAlpha($('model_id'),'Модел *');
				resetSelectToChooseAlpha($('engine_id'),'Двигател *');
				resetSelectToChooseAlpha($('inch_id'),'Диаметър на джантата');
				var modelsArr = eval('(' + transport.responseText + ')');
				for (var i = 0, model; model = modelsArr[i]; i++) {
					$('model_id').options[(i+1)] = new Option(model.option, model.id);
				}
				$('model_id').disabled = false;
			}
		});
	});
	Event.observe('model_id', 'change', function(evt) {
		new Ajax.Request('./ajax/getengine.php', {
			method: 'post',
			parameters: { 'model_id': $('model_id').value },
			onSuccess: function(transport) {
				resetSelectToChooseAlpha($('engine_id'),'Двигател *');
				resetSelectToChooseAlpha($('inch_id'),'Диаметър на джантата');
				var modelsArr = eval('(' + transport.responseText + ')');
				for (var i = 0, model; model = modelsArr[i]; i++) {
					$('engine_id').options[(i+1)] = new Option(model.option, model.id);
				}
				$('engine_id').disabled = false;
			}
		});
	});
	Event.observe('engine_id', 'change', function(evt) {
		new Ajax.Request('./ajax/getinches.php', {
			method: 'post',
			parameters: { 'engine_id': $('engine_id').value },
			onSuccess: function(transport) {
				resetSelectToChooseAlpha($('inch_id'),'Диаметър на джантата');
				var modelsArr = eval('(' + transport.responseText + ')');
				for (var i = 0, model; model = modelsArr[i]; i++) {
					$('inch_id').options[(i+1)] = new Option(model.option, model.id);
				}
				$('inch_id').disabled = false;
			}
		});
	});
});
function resetSelectToChooseAlpha(select,defopt) {
	while (select.options.length > 0) {
		select.options[0] = null;
	}
	select.options[0] = new Option(defopt, 0);
	$(select).disabled = true;
}