function calculate_payment() {
	cur_year =  document.getElementById('curyear').value;
	prod_year =  document.getElementById('prodyear').options[document.getElementById('prodyear').selectedIndex].value;
	engine_volume =  document.getElementById('enginevolume').options[document.getElementById('enginevolume').selectedIndex].value;	
	dollar_rate =  document.getElementById('dollarrate').value;;
	car_age = cur_year - prod_year;
	if (car_age  < 2) coef=1.5;
	if (car_age == 2) coef=1.4;
	if (car_age == 3) coef=1.3;
	if (car_age == 4) coef=1.2;
	if (car_age == 5) coef=1;
	if (car_age == 6) coef=0.7;
	if (car_age  > 6 &&car_age < 13) coef=0.5;
	if (car_age == 13) coef=0.6;
	if (car_age == 14) coef=0.7;
	if (car_age  > 14) coef=0.8;	
	
	

	document.getElementById('lab_excise').innerHTML = Math.round(coef*engine_volume);
	//document.getElementById('lab_custom_payment').innerHTML = Math.round(0.05*engine_volume*(1+0.05*car_age));	
	document.getElementById('lab_custom_payment').innerHTML = 150;
	document.getElementById('lab_import_payment').innerHTML = Math.round(engine_volume*0.05+engine_volume*car_age*0.0025);
	
	total = Math.round(coef*engine_volume+0.05*engine_volume*(1+0.05*car_age))+150+72;
	document.getElementById('lab_total').innerHTML = total;		
	document.getElementById('lab_total_dollar').innerHTML = Math.round(total/dollar_rate);		
}