//*******************************************
//DO NOT REMOVE THIS COPYWRITE INFO!
//Adjustable Rate Mortgage Calculator
//2004 Daniel C. Peterson ALL RIGHTS RESERVED
//Created: 10/18/2004
//Last Modified: 10/18/2004
//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 #:5114-1170-134-1128
//Commercial Licence Date:2007-12-22
//*******************************************



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 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 formatNumberDec(num, places, comma) {

var isNeg=0;

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

    var myDecFact = 1;
    var myPlaces = 0;
    var myZeros = "";
    while(myPlaces < places) {
       myDecFact = myDecFact * 10;
       myPlaces = eval(myPlaces) + eval(1);
       myZeros = myZeros + "0";
    }
    
	onum=Math.round(num*myDecFact)/myDecFact;
		
	integer=Math.floor(onum);

	if (Math.ceil(onum) == integer) {
		decimal=myZeros;
	} else{
		decimal=Math.round((onum-integer)* myDecFact)
	}
	decimal=decimal.toString();
	if (decimal.length<places) {
        fillZeroes = places - decimal.length;
	   for (z=0;z<fillZeroes;z++) {
        decimal="0"+decimal;
        }
     }

   if(places > 0) {
      decimal = "." + decimal;
   }

   if(comma == 1) {
	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;
   } else {
      finNum=integer+""+decimal;
   }

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

	return finNum;
}


function computeForm(report, lang) {

var alert_txt = "";

if(document.calc.principal.value == 0 || document.calc.principal.value == "") {
   alert("Please enter the mortgage's principal amount.");
   document.calc.principal.focus();
} else
if(document.calc.start_rate.value == 0 || document.calc.start_rate.value == "") {
   alert("Please enter the beginning annual interest rate.");
   document.calc.start_rate.focus();
} else
if(document.calc.start_months.value == 0 || document.calc.start_months.value == "") {
   alert("Please enter the number of months the rate will be fixed.");
   document.calc.start_months.focus();
} else
if(document.calc.adjust_months.value == 0 || document.calc.adjust_months.value == "") {
   alert("Please enter the number of months between rate adjustments.");
   document.calc.adjust_months.focus();
} else
if(document.calc.adjust_amt.value == 0 || document.calc.adjust_amt.value == "") {
   alert_txt = "Please enter the expected amount of each adjustment (eg. \".25\" if rates ";
   alert_txt += "are expected to increase or \"-.25\" if rates are expected to decrease)";
   alert(alert_txt);
   document.calc.adjust_amt.focus();
} else
if(document.calc.rate_cap.value == 0 || document.calc.rate_cap.value == "") {
   alert("Please enter the maximum allowable interest rate (rate cap).");
   document.calc.rate_cap.focus();
} else {

var Vprincipal = stripNum(document.calc.principal.value);

var Vstart_rate = stripNum(document.calc.start_rate.value);

var VnumYears_idx = document.calc.numYears.selectedIndex;
var VnumYears = document.calc.numYears.options[VnumYears_idx].value;
var term_months = VnumYears * 12;

var Vstart_pmt = computeMonthlyPayment(Vprincipal, term_months, Vstart_rate);


var Vstart_months = stripNum(document.calc.start_months.value);
var Vadjust_months = stripNum(document.calc.adjust_months.value);
var Vadjust_amt = stripNum(document.calc.adjust_amt.value);
var Vrate_cap = stripNum(document.calc.rate_cap.value);

if(Vstart_rate > 25) {
   alert("Please enter a starting interest rate that is less than or equal to 25.000%.");
   document.calc.start_rate.focus();
} else
if(Vrate_cap < 5) {
   alert("Please enter a rate cap that is greater than or equal to 5.000%.");
   document.calc.rate_cap.focus();
} else
if(Vrate_cap > 25) {
   alert("Please enter a rate cap that is less than or equal to 25.000%.");
   document.calc.rate_cap.focus();
} else
if(Vprincipal < 100) {
   alert("Please enter a mortgage loan amount that is greater than $100.");
   document.calc.principal.focus();
} else
if(Vprincipal > 100000000) {
   alert("Please enter a mortgage loan amount that is less than $100,000,000.");
   document.calc.principal.focus();
} else
if(Vstart_months > 120) {
   alert("Number of months before adjustments must be less than or equal to 120.");
   document.calc.start_months.focus();
} else
if(Vadjust_months > 12) {
   alert("Number of months between adjustments must be less than or equal to 12.");
   document.calc.adjust_months.focus();
} else
if(Vadjust_amt > 3) {
   alert("Rate adjustment amount must be less than or equal to 3.000%.");
   document.calc.adjust_amt.focus();
} else
if(Vadjust_amt < -3) {
   alert("Rate adjustment amount must be greater than or equal to -3.000%.");
   document.calc.adjust_amt.focus();
} else {

document.calc.start_pmt.value = "$" + formatNumberDec(Vstart_pmt,2,1);

var rate = Vstart_rate;
var old_rate = Vstart_rate;
var pmt = Vstart_pmt;
var accum_pmts = 0;
var new_rate = 0;
var prin = Vprincipal;
var int_port = 0;
var accum_int = 0;
var prin_port = 0;
var accum_prin = 0;
var cnt = 0;
var adjust_nprs = 0;
var new_term_months = 0;
var i = 0;

var pmtRows = "";

while(cnt < term_months) {

   cnt += 1;

   if(cnt <= Vstart_months) {
      rate = Vstart_rate;
   } else {
      if((eval(cnt)-eval(1)) % Vadjust_months == 0) {
         adjust_nprs += 1;
         new_term_months = eval(term_months) - eval(cnt) + eval(1);
         rate = eval(adjust_nprs * Vadjust_amt) + eval(Vstart_rate);
         if(rate < 2) {
            rate = 2;
         }
         if(rate > Vrate_cap) {
            rate = Vrate_cap;
         }
         pmt = computeMonthlyPayment(prin, new_term_months, rate);
      }
   }



   i = rate / 100 / 12;

   if(cnt < term_months) {

      int_port = Math.round(prin * i * 100) / 100;
      accum_int += int_port;
      prin_port= eval(pmt) - eval(int_port);
      accum_prin = eval(accum_prin) + eval(prin_port);
      prin = eval(prin) - eval(prin_port);

   } else {

      int_port = Math.round(prin * i * 100) / 100;
      accum_int += int_port;
      prin_port= prin;
      accum_prin = eval(accum_prin) + eval(prin_port);
      prin = eval(prin) - eval(prin_port);
      pmt = eval(prin_port) + eval(int_port);
   }

   accum_pmts += pmt;

   if(report == 1) {
      pmtRows = "" + pmtRows + "<tr><td align=right><font face='arial'><small>" + cnt + "</small>";
      pmtRows += "</font></td><td align=right><font face='arial'>";
      pmtRows += "<small>" + formatNumberDec(rate,2,1) + "%</small></font></td>";
      pmtRows += "<td align=right><font face='arial'><small>$" + formatNumberDec(pmt,2,1) + "</small>";
      pmtRows += "</font></td><td align=right><font face='arial'>";
      pmtRows += "<small>$" + formatNumberDec(prin_port,2,1) + "</small></font></td>";
      pmtRows += "<td align=right><font face='arial'>";
      pmtRows += "<small>$" + formatNumberDec(int_port,2,1) + "</small></font></td>";
      pmtRows += "<td align=right><font face='arial'>";
      pmtRows += "<small>$" + formatNumberDec(prin,2,1) + "</small></font></td></tr>";
   }

}


document.calc.total_pmts.value = "$" + formatNumberDec(accum_pmts,2,1);
document.calc.total_int.value = "$" + formatNumberDec(accum_int,2,1);
if(pmt > Vstart_pmt) {
   document.calc.max_pmt.value = "$" + formatNumberDec(pmt,2,1);
} else {
   document.calc.max_pmt.value = "$" + formatNumberDec(Vstart_pmt,2,1);
}

if(report == 1) {

var part1 = "<head><title>Amortization Schedule</title></head>" + "<body bgcolor= '#FFFFFF'>";
part1 += "<br><br><center><font face='arial'><big>";
part1 += "<strong>Adjustable Rate Mortgage Summary</strong></big></font></center><br>";


var part2 = "<center><table border=1 cellpadding=2 cellspacing=0 bordercolor='#EEEEEE'>";
part2 += "<tr><td colspan=4><font face='arial'><small>Mortgage loan amount:</small></font></td>";
part2 += "<td colspan='2' align='right'><font face='arial'>";
part2 += "<small>$" + formatNumberDec(Vprincipal,2,1) + "</small></font></td></tr>";
part2 += "<tr><td colspan=4><font face='arial'><small>Mortgage term:</small></font></td>";
part2 += "<td colspan='2' align='right'><font face='arial'><small>" + VnumYears + " years</small>";
part2 += "</font></td></tr><tr><td colspan=4><font face='arial'><small>Beginning interest rate:";
part2 += "</small></font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>" + formatNumberDec(Vstart_rate,3,0) + "%</small></font></td></tr>";
part2 += "<tr><td colspan=4><font face='arial'><small>Beginning monthly payment:";
part2 += "</small></font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>$" + formatNumberDec(Vstart_pmt,2,1) + "</small></font></td></tr>";
part2 += "<tr><td colspan=4><font face='arial'><small>Interest rate cap:</small>";
part2 += "</font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>" + formatNumberDec(Vrate_cap,3,0) + "%</small></font></td></tr>";
part2 += "<tr><td colspan=4><font face='arial'><small>Expected rate adjustment amount:";
part2 += "</small></font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>" + formatNumberDec(Vadjust_amt,2,0) + "%</small></font></td></tr>";
part2 += "<tr><td colspan=4><font face='arial'><small>Initial fixed rate period:</small>";
part2 += "</font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>" + Vstart_months + " months</small></font></td></tr><tr>";
part2 += "<td colspan=4><font face='arial'><small>";
part2 += "Adjustment period:</small></font></td><td colspan='2' align='right'>";
part2 += "<font face='arial'><small>" + Vadjust_months + " months</small>";
part2 += "</font></td></tr><tr><td colspan=4><font face='arial'><small>Total of all";
part2 += " monthly payments:</small></font></td><td colspan='2' align='right'>";
part2 += "<font face='arial'><small>$" + formatNumberDec(accum_pmts,2,1) + "</small>";
part2 += "</font></td></tr><tr><td colspan=4><font face='arial'><small>Total interest:";
part2 += "</small></font></td><td colspan='2' align='right'><font face='arial'>";
part2 += "<small>$" + formatNumberDec(accum_int,2,1) + "</small></font></td></tr>";
part2 += "<tr><td colspan=6><center><font face='arial'><b>Schedule of Payments</b>";
part2 += "</font><br><font face='arial'><small><small>Please allow for slight ";
part2 += "rounding differences.</small></small></font></center></td></tr>";
part2 += "<tr bgcolor='silver'><td align='center'><font face='arial'><small>";
part2 += "<b>Pmt #</b></small></font></td><td align='center'><font face='arial'>";
part2 += "<small><b>Rate</b></small></font></td><td align='center'>";
part2 += "<font face='arial'><small><b>Payment</b></small></font></td>";
part2 += "<td align='center'><font face='arial'><small><b>Principal</b></small>";
part2 += "</font></td><td align='center'><font face='arial'><small><b>Interest</b>";
part2 += "</small></font></td><td align='center'><font face='arial'><small>";
part2 += "<b>Balance</b></small></font></td></tr>";



var part3 = ("" + pmtRows + "");



var part4 = "<tr><td colspan='2'><font face='arial'><small><b>Grand Total</b></small>";
part4 += "</font></td><td align=right><font face='arial'><small>";
part4 += "<b>$" + formatNumberDec(accum_pmts,2,1) + "</b></small></font>";
part4 += "</td><td align=right><font face='arial'><small>";
part4 += "<b>$" + formatNumberDec(accum_prin,2,1) + "</b></small></font></td>";
part4 += "<td align=right><font face='arial'><small>";
part4 += "<b>$" + formatNumberDec(accum_int,2,1) + "</b></small></font></td>";
part4 += "<td> </td></tr></table><br><center><form method='post'>";
part4 += "<input type='button' value='Close Window' onClick='window.close()'>";
part4 += "</form></center></body></html>";



var schedule = (part1 + "" + part2 + "" + part3 + "" + part4 + "");



  reportWin = window.open("","","width=500,height=400,toolbar=yes,menubar=yes,scrollbars=yes");

  reportWin.document.write(schedule);

  reportWin.document.close();

}

      }


   }

}

function clearResults(form) {

document.calc.start_pmt.value = "";
document.calc.total_pmts.value = "";
document.calc.total_int.value = "";
document.calc.max_pmt.value = "";
}