var dRatesLow = new Array("2.20", "2.40", "2.60"  ,"3.10", "3.50", "3.80");
var dRatesHigh = new Array("2.20", "2.40", "2.60"  ,"3.10", "3.50", "3.80");

function PeriodChange()
{
	var deposit = document.contactform.deposit.value;
	if(deposit=="")
	{
		alert("Gaarne hoofdsom invoeren");
		document.contactform.deposit.focus();
		return;
	}
	var iDeposit = eval(deposit);
	var iPeriod = document.contactform.period.selectedIndex;	
	if(iDeposit<1000)
	{
		alert("Minimale inleg is €1.000");
		document.contactform.deposit.focus();		
		return;
	}
	else if(iDeposit<40000)
	{
		document.contactform.interest_rate.value = dRatesLow[iPeriod];
		return;
	}
	else
	{
		document.contactform.interest_rate.value = dRatesHigh[iPeriod];		
		return;
	}

}

function CalculateInterest()
{
	var deposit = document.contactform.deposit.value;
	if(deposit=="")
	{
		alert("Gaarne hoofdsom invoeren");
		document.contactform.deposit.focus();
		return;
	}
	var iDeposit = eval(deposit);
	var iPeriod = document.contactform.period.selectedIndex;	
	if(iDeposit<1000)
	{
		alert("Minimale inleg is €1.000");
		document.contactform.deposit.focus();		
		return;
	}	
	var periodyear = document.contactform.period.options[document.contactform.period.selectedIndex].value;
	var rate = document.contactform.interest_rate.value;
	var interest = deposit*periodyear*rate/100;
	
	interest = interest*100;
	interest = Math.round(interest);
	interest = interest / 100;
	var total = Number(deposit) + Number(interest);
	document.contactform.total.value = total;	
}