function do_update(value, action, target) {

		var url = 'part_search_ajax.php?action=' + action;
		var params = 'id=' + value;
	
		var myAjax = new Ajax.Updater(
				target,
				url,
				{
					method: 'get',
					parameters: params
				});

	}

	function update_model() {
		var make = $F('make_select');
		if (make !== "0") {
			select_loading('model_select');
			do_update(make, 'update_model', 'model_select_div');
		}
	}
	
	function update_year() {
		var model = $F('model_select');
		select_loading('year_select');
		do_update(model, 'update_year', 'year_select_div');
	}
	
	function update_engine() {
		var year = $F('year_select');
		pars = year + '&model=' + $F('model_select');
		select_loading('engine_select');
		do_update(pars, 'update_engine', 'engine_select_div');
	}
	
	function update_submit() {
		search_submit = $('search_submit');
		search_submit.disabled = false;
	
	}
	
	function add_form_actions() {
		$('make_select').onchange = function() {update_model()};
		$('model_select').onchange = function() {update_year()};
		$('year_select').onchange = function() {update_engine()};
	}

	
	
	function select_loading(target) {
		box = $(target);
		box.disabled = true;
		box.options.length = 0;
		box.options[0] = new Option('loading.....', '');
	}