var rates_amount;
var rates_currency;

var price_metro = 14;
var price_coffe = 60;
var price_ticket = 300;
var price_bigmak = 55;

function ConvertCurrency(){
	rates_amount = GetObj('cur_amount');
	rates_currency = GetObj('cur_currency');
	
	if(!CheckRatesForm()){
		return false;
	}
	
	roubles = rates_amount.value*currency_list[rates_currency.value][0];
	roubles = RoundResConvert(roubles);
	
	ConvertResultString(roubles);
	ConvertResultThings(roubles);
}

function CheckRatesForm(){
	if(!IsInt(rates_amount.value)){
		alert('Field "Amount" can contain only figures');
		rates_amount.focus();
		return false;
	}
	
	if(rates_currency.value == 0){
		alert("Please, select currency.");
		rates_currency.focus();
		return false;
	}
	
	return true;
}

function ConvertResultString(roubles){
	res_div = GetObj('convert_result_d');
	res_div.innerHTML = rates_amount.value + ' ' + currency_list[rates_currency.value][1] + ' = ' + roubles + ' Russian roubles.';
	
	res_span = GetObj('convert_res_rub');
	res_span.innerHTML = roubles;
}

function ConvertResultThings(roubles){
	//metro
	metro = roubles/price_metro;
	metro = RoundResConvert(metro);
	metro_obj = GetObj('currency_metro');
	metro_obj.innerHTML = metro;
	
	//coffe
	coffe = roubles/price_coffe;
	coffe = RoundResConvert(coffe);
	coffe_obj = GetObj('currency_coffe');
	coffe_obj.innerHTML = coffe;

	//ticket
	ticket = roubles/price_ticket;
	ticket = RoundResConvert(ticket);
	ticket_obj = GetObj('currency_ticket');
	ticket_obj.innerHTML = ticket;

	//bigmak
	bigmak = roubles/price_bigmak;
	bigmak = RoundResConvert(bigmak);
	bigmak_obj = GetObj('currency_bigmak');
	bigmak_obj.innerHTML = bigmak;	
}

function RoundResConvert(value){
	return (Math.round(value * 100) / 100); 
}