function CalculateTotalPrice(callingObject)
{
	var num = document.getElementById(callingObject).value;
	var priceInfo = document.getElementById("priceInfo");
	if (CheckNumeric((num)))
	{
		var objectPrice = GetPriceOfSelectedObject();
		var totalPrice = FormatAsCurrency(objectPrice * Math.floor(num));
		priceInfo.innerHTML = "Totaalprijs: € "  + totalPrice;
	}
	else
	{
		priceInfo.innerHTML = "Geen geldige aantal ingevoerd.";
	}
}

function GetPriceOfSelectedObject()
{
	var selectBox = document.getElementById("form_openanswer_16");
	var boxID = selectBox.options[selectBox.selectedIndex].value;
	var boxPrice = prices[hex_md5(boxID)];
	return boxPrice.replace(",",".");
}

function CheckNumeric(value)
{
	var anum=/(^\d+$)|(^\d+\.\d+$)/
	if (anum.test(value))
	{
		return true;
	}
	else
	{
		return false;
	}
}

function FormatAsCurrency(number)
{
	var formatted = number + '';
	formatted = formatted.replace(".",",");
	if (number == Math.floor(number))
	{
		return formatted + ",-";
	}
	else if (number == (Math.round(number * 10) / 10))
	{
		return (formatted + "0");
	}
	else if (number == (Math.round(number * 100) / 100))
	{
		return (formatted);
	}
	else
	{
		number = Math.round(number * 100) / 100; 
		return FormatAsCurrency(number);
	}
}