//////////////////////////////////////////////////////////////////////////////////////

function calculate_loan()
{
	var a = document.loan.downpay.value;
	var b = document.loan.loanselling.value;
	var b3 = document.loan.loanmonths.value;
	var b4 = document.loan.loaninterest.value;
	//alert(a);
	//alert(b);
	if (parseFloat(a)>parseFloat(b)){alert("Down Payment should not be greater than Selling Price");document.loan.downpay.focus();return false;}
	var c = parseInt(parseFloat(b) - parseFloat(a));
	document.loan.loanamount.value = c;
     b4 = b4.substring(0,b4.length -1) / 100;
	//b4 = parseInt(b4) / 100;
	var b10 = c;
	var upper = b10 * ( b4 / 12);
	if(upper==0)  {
		document.loan.loanpayment.value=c/b3;
   		document.loan.loantotal.value=upper;
  	}
  	else {
 		var lower = 1 - ( 1 / Math.pow ( (1+ (b4 / 12)),b3) );
 		var monthly_payment = upper / lower + " ";
 		document.loan.loanpayment.value =monthly_payment.substring(0,monthly_payment.indexOf('.')) + monthly_payment.substring(monthly_payment.indexOf('.'),monthly_payment.indexOf('.')+3) ;
 		interestamount = (monthly_payment*b3) - b10;
 		interestamount = interestamount + " ";
 		document.loan.loantotal.value = interestamount.substring(0,interestamount.indexOf('.')) + interestamount.substring(interestamount.indexOf('.'),interestamount.indexOf('.')+3) ;
	}
	return false;
}