// Loans Calculator Javascript
// James - 16/04/08
function viewinput1(){
document.getElementById('input1').style.display = "block";
document.getElementById('input2').style.display = "none";
document.getElementById('input3').style.display = "none";
document.getElementById('resultbox').style.display = "none";
document.getElementById('inactive1').style.display = "none";
document.getElementById('active1').style.display = "block";
document.getElementById('inactive2').style.display = "block";
document.getElementById('active2').style.display = "none";
document.getElementById('inactive3').style.display = "block";
document.getElementById('active3').style.display = "none";
}
function viewinput2(){
document.getElementById('input1').style.display = "none";
document.getElementById('input2').style.display = "block";
document.getElementById('input3').style.display = "none";
document.getElementById('resultbox').style.display = "none";
document.getElementById('inactive1').style.display = "block";
document.getElementById('active1').style.display = "none";
document.getElementById('inactive2').style.display = "none";
document.getElementById('active2').style.display = "block";
document.getElementById('inactive3').style.display = "block";
document.getElementById('active3').style.display = "none";
}
function viewinput3(){
document.getElementById('input1').style.display = "none";
document.getElementById('input2').style.display = "none";
document.getElementById('input3').style.display = "block";
document.getElementById('resultbox').style.display = "none";
document.getElementById('inactive1').style.display = "block";
document.getElementById('active1').style.display = "none";
document.getElementById('inactive2').style.display = "block";
document.getElementById('active2').style.display = "none";
document.getElementById('inactive3').style.display = "none";
document.getElementById('active3').style.display = "block";
}
function formatCurrencyZeroDP(num) {
num = num.toString().replace(/\$|\,/g,'');
if(isNaN(num))
num = "0";
sign = (num == (num = Math.abs(num)));
num = Math.floor(num*100+0.50000000001);
cents = num%100;
num = Math.floor(num/100).toString();
if(cents<10)
cents = "0" + cents;
for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
num = num.substring(0,num.length-(4*i+3))+','+
num.substring(num.length-(4*i+3));
//return (((sign)?'':'-') + '$' + num + '.' + cents);
return (((sign)?'':'-') + num + '.' + cents);
}
function formatCurrencyZeroDP(num) {
num = num.toString().replace(/\$|\,/g,'');
if(isNaN(num))
num = "0";
sign = (num == (num = Math.abs(num)));
num = Math.floor(num*100+0.50000000001);
cents = num%100;
num = Math.floor(num/100).toString();
if(cents<10)
cents = "0" + cents;
for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
num = num.substring(0,num.length-(4*i+3))+','+
num.substring(num.length-(4*i+3));
//return (((sign)?'':'-') + '$' + num + '.' + cents);
return (((sign)?'':'-') + num);
}
function borrowingCosts(){
var validated = true;
//declare key variables
var Loan = document.getElementById("LoanAmount").value;
Loan = parseFloat(Loan.replace(/[^0-9.]/g, ''));
if(isNaN(Loan) || (Loan == 0)){
document.getElementById("LoanAmount").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("LoanAmount").style.border = "";
}
var Rate = document.getElementById("InterestRate").value;
Rate = parseFloat(Rate.replace(/[^0-9.]/g, ''));
if(isNaN(Rate)){
document.getElementById("InterestRate").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("InterestRate").style.border = "";
}
var temp = document.getElementById("Term").value;
temp = parseFloat(temp.replace(/[^0-9.]/g, ''));
var Term = new Number(temp);
Term = parseFloat(Term);
if(isNaN(Term) || (Term == 0)){
document.getElementById("Term").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("Term").style.border = "";
}
if(validated){
document.getElementById("LoanAmount").style.border = "";
document.getElementById("InterestRate").style.border = "";
document.getElementById("Term").style.border = "";
//repayment amount
var MonthlyRate = Rate/1200;
var TermMonths = Term * -1;
var Multiplier = 1 + MonthlyRate;
Multiplier = Math.pow(Multiplier, TermMonths);
Multiplier = 1 - Multiplier;
Multiplier = MonthlyRate / Multiplier;
var RepaymentAmount = Loan * Multiplier;
//display
var resultText = "To borrow £"+Loan+", it will cost £"+formatCurrencyZeroDP(RepaymentAmount)+"/month
";
resultText = resultText + "Over the life of the loan, this costs £"+formatCurrencyZeroDP(((RepaymentAmount*Term)-Loan))+" in interest
";
} else {
var resultText = "Please insert values in every box.
";
}
document.getElementById("Rresults").innerHTML = resultText;
document.getElementById("resultbox").style.display= "block";
}
function howMuch(){
var validated = true;
var RepaymentAmount = document.getElementById("RepaymentAmount").value;
RepaymentAmount = parseFloat(RepaymentAmount.replace(/[^0-9.]/g, ''));
if(isNaN(RepaymentAmount) ||(RepaymentAmount ==0)){
document.getElementById("RepaymentAmount").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("RepaymentAmount").style.border = "";
}
var Rate = document.getElementById("InterestRate3").value;
Rate = parseFloat(Rate.replace(/[^0-9.]/g, ''));
if(isNaN(Rate)){
document.getElementById("InterestRate3").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("InterestRate3").style.border = "";
}
var temp = document.getElementById("Term3").value;
temp = parseFloat(temp.replace(/[^0-9.]/g, ''));
var Term = new Number(temp);
Term = parseFloat(Term);
if(isNaN(Term) || (Term ==0)){
document.getElementById("Term3").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("Term3").style.border = "";
}
if(validated){
document.getElementById("RepaymentAmount").style.border = "";
document.getElementById("InterestRate3").style.border = "";
document.getElementById("Term3").style.border = "";
var InterestRate = document.getElementById("InterestRate3").value;
var MonthlyRate = Rate/1200;
var TermMonths = Term * -1;
var Multiplier = 1 + MonthlyRate;
Multiplier = Math.pow(Multiplier, TermMonths);
Multiplier = 1 - Multiplier;
Multiplier = MonthlyRate / Multiplier;
var Loan = RepaymentAmount / Multiplier;
var interestPaid = formatCurrencyZeroDP((RepaymentAmount*Term)-Loan) ;
Loan = formatCurrencyZeroDP(Loan);
//display
var resultText = "Repaying £"+formatCurrencyZeroDP(RepaymentAmount)+"/month, over "+Term+" months,
you will be able to borrow £"+formatCurrencyZeroDP(Loan)+"
Explanation:
The total repayment is £"+formatCurrencyZeroDP(RepaymentAmount*Term)+", made up of the original £"+formatCurrencyZeroDP(Loan)+"
plus the £"+formatCurrencyZeroDP(interestPaid)+" interest you’d repay at "+(InterestRate)+"%";
} else {
var resultText = "Please insert values in every box.
";
}
document.getElementById("Rresults").innerHTML = resultText;
document.getElementById("resultbox").style.display= "block";
}
function switchingLoans(){
var validated = true;
var Loan = document.getElementById("LoanAmount2").value;
Loan = parseFloat(Loan.replace(/[^0-9.]/g, ''));
if(isNaN(Loan) || (Loan == 0)){
document.getElementById("LoanAmount2").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("LoanAmount2").style.border = "";
}
var Payment = document.getElementById("MonthlyPayment").value;
Payment = parseFloat(Payment.replace(/[^0-9.]/g, ''));
if(isNaN(Payment) || (Payment == 0)){
document.getElementById("MonthlyPayment").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("MonthlyPayment").style.border = "";
}
var Rate = document.getElementById("InterestRate2").value;
Rate = parseFloat(Rate.replace(/[^0-9.]/g, ''));
if(isNaN(Rate)){
document.getElementById("InterestRate2").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("InterestRate2").style.border = "";
}
var temp = document.getElementById("Term2").value;
temp = parseFloat(temp.replace(/[^0-9.]/g, ''));
var Term = new Number(temp);
Term = parseFloat(Term);
if(isNaN(Term) || (Term == 0)){
document.getElementById("Term2").style.border = "#ff0000 solid 1px";
validated = false;
} else {
document.getElementById("Term2").style.border = "";
}
if(validated){
var MonthlyRate = Rate/1200;
var TermMonths = Term * -1;
var Multiplier = 1 + MonthlyRate;
Multiplier = Math.pow(Multiplier, TermMonths);
Multiplier = 1 - Multiplier;
Multiplier = MonthlyRate / Multiplier;
var RepaymentAmount = Loan * Multiplier;
var repayment = Payment * Term;
var final = repayment - (RepaymentAmount * Term);
RepaymentAmount = formatCurrencyZeroDP(RepaymentAmount);
document.getElementById("Rresults").innerHTML = "£"+RepaymentAmount+" - £"+formatCurrencyZeroDP(repayment)+ " = £"+formatCurrencyZeroDP(final)+"";
if(final > 0){
var resultText =" You CAN save by switching
Stick with your current deal and you will repay £"+formatCurrencyZeroDP(Math.round(repayment))+"
Shift to the new deal and you will repay £"+formatCurrencyZeroDP(Math.round(RepaymentAmount * Term))+"
Therefore you are £"+formatCurrencyZeroDP(Math.round(final))+" better off by switching";
} else {
var resultText =" You will NOT save by switching
Stick with your current deal and you will repay £"+formatCurrencyZeroDP(Math.round(repayment))+"
Shift to the new deal and you will repay £"+formatCurrencyZeroDP(Math.round(RepaymentAmount * Term))+"
Therefore you are £"+formatCurrencyZeroDP(Math.round(final*-1))+" worse off by switching";
}
} else {
var resultText = "Please insert values in every box.
";
}
document.getElementById("Rresults").innerHTML = resultText;
document.getElementById("resultbox").style.display= "block";
}