function preload() {
	var flag_nl=new Image();
	var flag_us=new Image();
	flag_nl.src='images/nl.png';
	flag_us.src='images/us.png';
}

function CurrencyFormatted(amount)
{
	var i = parseFloat(amount);
	if(isNaN(i)) { i = 0.00; }
	var minus = '';
	if(i < 0) { minus = '-'; }
	i = Math.abs(i);
	i = parseInt((i + .005) * 100);
	i = i / 100;
	s = new String(i);
	if(s.indexOf('.') < 0) { s += '.00'; }
	if(s.indexOf('.') == (s.length - 2)) { s += '0'; }
	s = minus + s;
	return s;
}

function calculate() {
	var number_servers;
	var number_domains;
	var number_contacts;
	var price_monthly;
	var power_checking;
	var subscription_term;

	number_servers = document.getElementById('number_servers').value;
	number_domains = document.getElementById('number_domains').value;
	number_contacts = document.getElementById('number_contacts').value;
	power_checking = document.getElementById('power_checking');
	subscription_term = document.getElementById('subscription_term').value;

	price_monthly = number_servers * 7.5;

	if (number_domains > 1) {
		price_monthly = price_monthly + ((number_domains - 1) * 1);
	}

	if (number_contacts > 1) {
		price_monthly = price_monthly + ((number_contacts - 1) * 2.5);
	}

	if (power_checking.checked == 1) {
		price_monthly = price_monthly + (number_servers * 2.5);		
	}

	document.getElementById('price').innerHTML = CurrencyFormatted(price_monthly*subscription_term);
}