function set_classes (year_select, class_select, include_all) {

	var all_gens = new Array(
		'Fun Runs',
		'Jets & Misc.'
	);
	var classes_gen1 = new Array(
		'D',
		'C',
		'B',
		'Quick',
		'Frantic/Shootout'
	);
	var classes_gen2 = new Array(
		'Super Street',
		'Super Mod',
		'Super Quick',
		'Pro FWD',
		'Pro Outlaw'
	);

	class_select.options.length = 0;

	var classes_for_year = new Array();

	if (include_all == 'include_all') {
		classes_for_year[0] = 'All';	// 'All' should always be first/top
	}

	if (year_select.options[year_select.selectedIndex].text == 'All') {
		classes_for_year = classes_for_year.concat(classes_gen1);
		classes_for_year = classes_for_year.concat(classes_gen2);
	}
	else if ( get_generation(year_select.options[year_select.selectedIndex].text ) == 'gen1') {
		classes_for_year = classes_for_year.concat(classes_gen1);
	}
	else if ( get_generation(year_select.options[year_select.selectedIndex].text ) == 'gen2') {
		classes_for_year = classes_for_year.concat(classes_gen2);
	}

	classes_for_year = classes_for_year.concat(all_gens);

	for (class_index in classes_for_year) {
		class_select.options[class_index] = new Option(
			classes_for_year[class_index],
			classes_for_year[class_index]
		);
	}

}

function get_generation (year) {
	if (year == '2005' || year == '2006' || year == '2007') {
		return 'gen1';
	}
	else {
		return 'gen2';
	}
}