//*******************************************
//DO NOT REMOVE THIS COPYWRITE INFO!
//Auto Payment Comparison Calculator
//2002 Daniel C. Peterson ALL RIGHTS RESERVED
//Created: 04/26/2002
//Last Modified: 03/17/2003
//This script may not be copied, edited, distributed or reproduced
//without express written permission from
//Daniel C. Peterson of Web Winder Website Services
//For commercial use rates, contact:
//Dan Peterson:
//Web Winder Website Services
//P.O. Box 11
//Bemidji, MN  56619
//dan@webwinder.com
//http://www.webwinder.com
//Commercial User Licence #:5782-1237-4-1198
//Commercial Licence Date:2008-09-11
//*******************************************



function stripNum(num) {

   num=num.toString();


   var len = num.length;
   var rnum = "";
   var test = "";
   var j = 0;

   var b = num.substring(0,1);
   if(b == "-") {
      rnum = "-";
   }

   for(i = 0; i <= len; i++) {

      b = num.substring(i,i+1);

      if(b == "0" || b == "1" || b == "2" || b == "3" || b == "4" || b == "5" || b == "6" || b == "7" || b == "8" || b == "9" || b == ".") {
         rnum = rnum + "" + b;

      }

   }

   if(rnum == "" || rnum == "-") {
      rnum = 0;
   }

   rnum = Number(rnum);

   return rnum;

}



function formatCurrency(num) {

var isNeg=0;

    if(num < 0) {
       num=num*-1;
       isNeg=1;
    }

    
	onum=Math.round(num*100)/100;
		
	integer=Math.floor(onum);

	if (Math.ceil(onum) == integer) {
		decimal="00";
	} else{
		decimal=Math.round((onum-integer)*100)
	}
	decimal=decimal.toString();
	if (decimal.length<2) decimal="0"+decimal;

	integer=integer.toString();
	var tmpnum="";
	var tmpinteger="";
	var y=0;

	for (x=integer.length;x>0;x--) {
		tmpnum=tmpnum+integer.charAt(x-1);
		y=y+1;
		if (y==3 & x>1) {
			tmpnum=tmpnum+",";
			y=0;
		}
	}

	for (x=tmpnum.length;x>0;x--) {
		tmpinteger=tmpinteger+tmpnum.charAt(x-1);
	}
		
	finNum="$"+tmpinteger+"."+decimal;

    if(isNeg == 1) {
       finNum = "-" + finNum;
    }

	return finNum;
}




function computeMonthlyPayment(prin, numPmts, intRate) {

var pmtAmt = 0;

if(intRate == 0) {
   pmtAmt = prin / numPmts;
} else {
   
   if (intRate >= 1.0) {
     intRate = intRate / 100.0;
   }
   intRate /= 12;

   var pow = 1;
   for (var j = 0; j < numPmts; j++)
      pow = pow * (1 + intRate);

   pmtAmt = (prin * pow * intRate) / (pow - 1);

}

return pmtAmt;

}


function computeForm(form) {
if(document.pmtCalcForm.principal.value == 0 || document.pmtCalcForm.principal.value == "") {
   alert("Please enter the amount financed.");
   document.pmtCalcForm.principal.focus();
} else
if(document.pmtCalcForm.intRate.value == 0 || document.pmtCalcForm.intRate.value == "") {
   alert("Please enter the annual interest rate.");
   document.pmtCalcForm.intRate.focus();
} else
   {
var Vprincipal = stripNum(document.pmtCalcForm.principal.value);
var VintRate = stripNum(document.pmtCalcForm.intRate.value);

var Vpmt12 = computeMonthlyPayment(Vprincipal, 12, VintRate);
var Vpmt24 = computeMonthlyPayment(Vprincipal, 24, VintRate);
var Vpmt36 = computeMonthlyPayment(Vprincipal, 36, VintRate);
var Vpmt48 = computeMonthlyPayment(Vprincipal, 48, VintRate);
var Vpmt60 = computeMonthlyPayment(Vprincipal, 60, VintRate);
var Vpmt72 = computeMonthlyPayment(Vprincipal, 72, VintRate);

document.pmtCalcForm.pmt12.value = formatCurrency(Vpmt12);
document.pmtCalcForm.pmt24.value = formatCurrency(Vpmt24);
document.pmtCalcForm.pmt36.value = formatCurrency(Vpmt36);
document.pmtCalcForm.pmt48.value = formatCurrency(Vpmt48);
document.pmtCalcForm.pmt60.value = formatCurrency(Vpmt60);
document.pmtCalcForm.pmt72.value = formatCurrency(Vpmt72);
   }
}