// JScript File

function Reset()
{
    document.getElementById("ctl00_cntPlcMain_txtInterestRate").value = "";
    document.getElementById("ctl00_cntPlcMain_txtHowMuch").value = "";
    document.getElementById("ctl00_cntPlcMain_txtRepaymentPeriod").value = "";
    
    document.getElementById("CalculatorResult").style.display = "none";
}

//Calculator

function Calculate()
{
    if(Page_ClientValidate())
    {
        var interest = document.getElementById("ctl00_cntPlcMain_txtInterestRate").value / 100 / 12;
        var amount = document.getElementById("ctl00_cntPlcMain_txtHowMuch").value;
        var payments = document.getElementById("ctl00_cntPlcMain_txtRepaymentPeriod").value * 12;
        
        var interestOnly = CalculateInterestOnly(interest, amount, payments)
        var interestAndPayment = CalculateInterestAndPayment(interest, amount, payments)
        
        document.getElementById("lblInterestOnly").innerHTML = "£" + interestOnly.toFixed(2) + " (Interest only)";
        document.getElementById("lblRepayment").innerHTML = "£" + interestAndPayment.toFixed(2) + " (Repayment)";
        document.getElementById("CalculatorResult").style.display = "block";
    }
}

function CalculateInterestAndPayment(interest, amount, payments)
{    
    var resulta = Math.pow(1+interest,-payments);
    var result = interest/(1-resulta) * amount;
    
    return result;
}

function CalculateInterestOnly(interest, amount, payments)
{    
    var result = amount * interest;
    
    return result;
}