// *********************************************************
// ** Mortgage Calculator
// *********************************************************
 
var Months = 0;
var InterestRate = 0;
var LoanAmount = 0;
var TotalRepayments = 0;
		
// Change Loan value
function ChangeLoanAmount() {
	
	if ( Years.value == '' ) {
		alert( "You need to enter a number of Years" );
		Years.focus();
	}
	else if ( Interest.value == '' ) {
		alert( "You need to enter an Interest Rate" );
		Interest.focus();
	}
	else if ( Amount.value == '' ) {
		alert( "You need to enter an Loan Amount" );
		Amount.focus();
	}
	else {
	
		InterestRate = Interest.value / 100.0;
		Months = Years.value * 12;
		LoanAmount = parseInt(Amount.value);
		LoanAmount *= 1000;
		CalculateRepayments();
	}
}
	
// Calculate Repayments
function CalculateRepayments() {
	
	 InterestRate /= 12;

     var pow = 1;
     for (var j = 0; j < Months; j++)
		pow = pow * (1 + InterestRate);
        
     TotalRepayments = (LoanAmount * pow * InterestRate) / (pow - 1);
     Repayments.value = Math.round(TotalRepayments * 100 ) / 100;
		
}