function calculateMonthlyPayment(interestRate,loanTerm,principalAmount) { // var interestRate = parseFloat(document.SimpleInterest.InterestRate.value) // var loanTerm = parseInt(document.SimpleInterest.LoanTerm.value) // var principalAmount = parseFloat(document.SimpleInterest.PrincipalAmount.value) var i = interestRate/100.0/12.0 var tau = 1.0 + i var tauToTheN = Math.pow(tau, loanTerm ) ; var magicNumber = tauToTheN * i / (tauToTheN - 1.0 ) var MoPayment = Math.round(principalAmount * magicNumber* 100) / 100 var TotInterest = Math.round((principalAmount * magicNumber * loanTerm - principalAmount) * 100) / 100 document.getElementById('modloanamt').innerHTML = "$ "+Math.round(principalAmount *100)/100 document.getElementById('modintrate').innerHTML = interestRate+"%" document.getElementById('modloanterm').innerHTML = loanTerm+" months" document.getElementById('modpayment').innerHTML = "$ "+Math.round(MoPayment *100)/100 document.getElementById('modtotinterest').innerHTML = "$ "+Math.round(TotInterest *100)/100 document.getElementById('modtopayback').innerHTML = "$ "+Math.round((TotInterest+principalAmount) *100)/100 modal.style.display = "block"; } // Get the modal var modal = document.getElementById('myModal'); // Get the element that closes the modal var span = document.getElementsByClassName("close")[0]; // When the user clicks on (x), close the modal span.onclick = function() { modal.style.display = "none"; } // When the user clicks anywhere outside of the modal, close it window.onclick = function(event) { if (event.target == modal) { modal.style.display = "none"; } }