//*******************************************
//DO NOT REMOVE THIS COPYWRITE INFO!
//ARM vs Fixed Rate Mortgage Calculator
//2004 Daniel C. Peterson ALL RIGHTS RESERVED
//Created: 10/21/2004
//Last Modified: 10/21/2004
//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 #:4279-998-135-965
//Commercial Licence Date:2007-01-10
//*******************************************



function stripNum(num) {

var iPercent
var iDollar
var iSpace
var iComma
var numLength = num.length

//lalalla Line #114

if(numLength > 0) {

   num=num.toString();

   iPercent = num.indexOf("%");
   if(iPercent >= 0) {
      num=num.substring(0,iPercent) + "" + num.substring(iPercent + 1,numLength);
      numLength=num.length;
      }
   iDollar = num.indexOf("$");
   if(iDollar >= 0) {
      num=num.substring(0,iDollar) + "" + num.substring(iDollar + 1,numLength);
      numLength=num.length;
      }
   iSpace = num.indexOf(" ");
   if(iSpace >= 0) {
      num=num.substring(0,iSpace) + "" + num.substring(iSpace + 1,numLength);
      numLength=num.length;
      }
   iComma = num.indexOf(",");
   if(iComma >= 0) {
      while(iComma >=1) {
         num=num.substring(0,iComma) + "" + num.substring(iComma + 1,numLength);
         numLength=num.length;
         iComma = num.indexOf(",");
      }
      }

      num = eval(num);


} else {

num = 0;

}

return num;

}




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, form) {

if(form.principal.value == 0 || form.principal.value == "") {
   alert("Please enter the mortgage's principal amount.");
   form.principal.focus();
} else
if(form.adjust_amt.value == 0 || form.adjust_amt.value == "") {
   alert("Please enter the expected amount of each adjustment (eg. \".25\" if rates are expected to increase or \"-.25\" if rates are expected to decrease).");
   form.adjust_amt.focus();
} else
if(form.fixed_rate.value == 0 || form.fixed_rate.value == "") {
   alert("Please enter the annual interest rate for the fixed mortgage.");
   form.fixed_rate.focus();
} else
if(form.adj_start_rate.value == 0 || form.adj_start_rate.value == "") {
   alert("Please enter the interest rate for the fully amortizing adjustable mortgage.");
   form.adj_start_rate.focus();
} else
if(form.adj_start_months.value == 0 || form.adj_start_months.value == "") {
   alert("Please enter the number of months the rate will be fixed for the fully amortizing adjustable mortgage.");
   form.adj_start_months.focus();
} else
if(form.adj_rate_cap.value == 0 || form.adj_rate_cap.value == "") {
   alert("Please enter the maximum allowable interest rate (rate cap) for the fully amortizing adjustable rate mortgage.");
   form.adj_rate_cap.focus();
} else
if(form.io_start_rate.value == 0 || form.io_start_rate.value == "") {
   alert("Please enter the interest rate for the interest-only adjustable mortgage.");
   form.io_start_rate.focus();
} else
if(form.io_start_months.value == 0 || form.io_start_months.value == "") {
   alert("Please enter the number of months the rate will be fixed for the interest-only adjustable mortgage.");
   form.io_start_months.focus();
} else
if(form.io_rate_cap.value == 0 || form.io_rate_cap.value == "") {
   alert("Please enter the maximum allowable interest rate (rate cap) for the interest-only adjustable rate mortgage.");
   form.io_rate_cap.focus();
} else {

var Vprincipal = stripNum(form.principal.value);

var VnumYears = form.numYears.options[form.numYears.selectedIndex].value;
var term_months = VnumYears * 12;

var Vadjust_amt = stripNum(form.adjust_amt.value);

var Vfixed_rate = stripNum(form.fixed_rate.value);

var Vadj_start_rate = stripNum(form.adj_start_rate.value);
var Vadj_start_months = stripNum(form.adj_start_months.value);
var Vadj_rate_cap = stripNum(form.adj_rate_cap.value);

var Vio_start_rate = stripNum(form.io_start_rate.value);
var Vio_start_months = stripNum(form.io_start_months.value);
var Vio_rate_cap = stripNum(form.io_rate_cap.value);

if(Vprincipal < 100) {
   alert("Please enter a mortgage loan amount that is greater than $100.");
   form.principal.focus();
} else
if(Vprincipal > 100000000) {
   alert("Please enter a mortgage loan amount that is less than $100,000,000.");
   form.principal.focus();
} else
if(Vadjust_amt > 3) {
   alert("Rate adjustment amount must be less than or equal to 3.000%.");
   form.adjust_amt.focus();
} else
if(Vadjust_amt < -3) {
   alert("Rate adjustment amount must be greater than or equal to -3.000%.");
   form.adjust_amt.focus();
} else
if(Vadj_start_rate > 25) {
   alert("Please enter a starting interest rate for the fully amortizing adjustable rate mortgage that is less than or equal to 25.000%.");
   form.adj_start_rate.focus();
} else
if(Vadj_rate_cap < 5) {
   alert("Please enter a rate cap for the fully amortizing adjustable rate mortgage that is greater than or equal to 5.000%.");
   form.adj_rate_cap.focus();
} else
if(Vadj_rate_cap > 25) {
   alert("Please enter a rate cap for the fully amortizing adjustable rate mortgage that is less than or equal to 25.000%.");
   form.adj_rate_cap.focus();
} else
if(Vadj_start_months > 120) {
   alert("Number of months before adjustments for the fully amortizing adjustable rate mortgage must be less than or equal to 120.");
   form.adj_start_months.focus();

} else
if(Vio_start_rate > 25) {
   alert("Please enter a starting interest rate for the interest-only adjustable rate mortgage that is less than or equal to 25.000%.");
   form.io_start_rate.focus();
} else
if(Vio_rate_cap < 5) {
   alert("Please enter a rate cap for the interest-only adjustable rate mortgage that is greater than or equal to 5.000%.");
   form.io_rate_cap.focus();
} else
if(Vio_rate_cap > 25) {
   alert("Please enter a rate cap for the interest-only adjustable rate mortgage that is less than or equal to 25.000%.");
   form.io_rate_cap.focus();
} else
if(Vio_start_months > 120) {
   alert("Number of months before adjustments for the interest-only adjustable rate mortgage must be less than or equal to 120.");
   form.io_start_months.focus();
} else {



var Vfixed_pmt = computeMonthlyPayment(Vprincipal, term_months, Vfixed_rate);
Vfixed_pmt = Math.round(Vfixed_pmt * 100) / 100;
form.fixed_pmt.value = "$" + formatNumberDec(Vfixed_pmt,2,1);

var Vadj_start_pmt = computeMonthlyPayment(Vprincipal, term_months, Vadj_start_rate);
//Vadj_start_pmt = Math.round(Vadj_start_pmt * 100) / 100;
form.adj_start_pmt.value = "$" + formatNumberDec(Vadj_start_pmt,2,1);

var Vio_start_pmt = Vio_start_rate / 100 / 12 * Vprincipal;
form.io_start_pmt.value = "$" + formatNumberDec(Vio_start_pmt,2,1);

var fix_rate = Vfixed_rate;
var adj_rate = Vadj_start_rate;
var io_rate = Vio_start_rate;

var fix_pmt = Vfixed_pmt;
var adj_pmt = Vadj_start_pmt;
var io_pmt = Vio_start_pmt;

var fix_accum_pmts = 0;
var adj_accum_pmts = 0;
var io_accum_pmts = 0;

var fix_prin = Vprincipal;
var fix_int_port = 0;
var fix_accum_int = 0;
var fix_prin_port = 0;
var fix_accum_prin = 0;

var adj_prin = Vprincipal;
var adj_int_port = 0;
var adj_accum_int = 0;
var adj_prin_port = 0;
var adj_accum_prin = 0;

var io_prin = Vprincipal;
var io_int_port = 0;
var io_accum_int = 0;
var io_prin_port = 0;
var io_accum_prin = 0;

var cnt = 0;
var adj_adjust_nprs = 0;
var io_adjust_nprs = 0;
var Vadjust_months = 12;
var adj_new_term_months = 0;
var io_new_term_months = 0;

var fix_i = 0;
var adj_i = 0;
var io_i = 0;

var pmtRows = "";

while(cnt < term_months) {

   cnt += 1;

   if(cnt <= Vadj_start_months) {
      adj_rate = Vadj_start_rate;
   } else {
      if((eval(cnt)-eval(1)) % Vadjust_months == 0) {
         adj_adjust_nprs += 1;
         adj_new_term_months = eval(term_months) - eval(cnt) + eval(1);
         adj_rate = eval(adj_adjust_nprs * Vadjust_amt) + eval(Vadj_start_rate);
         if(adj_rate < 2) {
            adj_rate = 2;
         }
         if(adj_rate > Vadj_rate_cap) {
            adj_rate = Vadj_rate_cap;
         }
         adj_pmt = computeMonthlyPayment(adj_prin, adj_new_term_months, adj_rate);
         //adj_pmt = Math.round(adj_pmt * 100) / 100;
      }
   }


   if(cnt <= Vio_start_months) {
      io_rate = Vio_start_rate;
   } else {
      if((eval(cnt)-eval(1)) % Vadjust_months == 0) {
         io_adjust_nprs += 1;
         io_new_term_months = eval(term_months) - eval(cnt) + eval(1);
         io_rate = eval(io_adjust_nprs * Vadjust_amt) + eval(Vio_start_rate);
         if(io_rate < 2) {
            io_rate = 2;
         }
         if(io_rate > Vio_rate_cap) {
            io_rate = Vio_rate_cap;
         }
         io_pmt = Math.round(io_rate / 100 / 12 * Vprincipal * 100) / 100;
      }
   }


   fix_i = fix_rate / 100 / 12;
   adj_i = adj_rate / 100 / 12;

   if(cnt < term_months) {

      fix_int_port = Math.round(fix_prin * fix_i * 100) / 100;
      fix_accum_int += fix_int_port;
      fix_prin_port= eval(fix_pmt) - eval(fix_int_port);
      fix_accum_prin = eval(fix_accum_prin) + eval(fix_prin_port);
      fix_prin = eval(fix_prin) - eval(fix_prin_port);

      adj_int_port = Math.round(adj_prin * adj_i * 100) / 100;
      adj_accum_int += adj_int_port;
      adj_prin_port= eval(adj_pmt) - eval(adj_int_port);
      adj_accum_prin = eval(adj_accum_prin) + eval(adj_prin_port);
      adj_prin = eval(adj_prin) - eval(adj_prin_port);

   } else {

      fix_int_port = Math.round(fix_prin * fix_i * 100) / 100;
      fix_accum_int += fix_int_port;
      fix_prin_port= fix_prin;
      fix_accum_prin = eval(fix_accum_prin) + eval(fix_prin_port);
      fix_prin = eval(fix_prin) - eval(fix_prin_port);
      fix_pmt = eval(fix_prin_port) + eval(fix_int_port);

      adj_int_port = Math.round(adj_prin * adj_i * 100) / 100;
      adj_accum_int += adj_int_port;
      adj_prin_port= adj_prin;
      adj_accum_prin = eval(adj_accum_prin) + eval(adj_prin_port);
      adj_prin = eval(adj_prin) - eval(adj_prin_port);
      adj_pmt = eval(adj_prin_port) + eval(adj_int_port);
   }

   fix_accum_pmts += fix_pmt;
   adj_accum_pmts += adj_pmt;
   io_accum_pmts += io_pmt;
   io_accum_int += io_pmt;

if(report == 1) {
    pmtRows = ("" + pmtRows + "<tr><td align=right><font face='arial'><small>" + cnt + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(fix_pmt,2,1) + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(fix_prin,2,1) + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(adj_pmt,2,1) + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(adj_prin,2,1) + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(io_pmt,2,1) + "</small></font></td><td align=right><font face='arial'><small>$" + formatNumberDec(io_prin,2,1) + "</small></font></td></tr>");
}

}

form.fixed_total_pmts.value = "$" + formatNumberDec(fix_accum_pmts,2,1);
form.fixed_total_int.value = "$" + formatNumberDec(fix_accum_int,2,1);
form.fixed_max_pmt.value = "$" + formatNumberDec(Vfixed_pmt,2,1);


form.adj_total_pmts.value = "$" + formatNumberDec(adj_accum_pmts,2,1);
form.adj_total_int.value = "$" + formatNumberDec(adj_accum_int,2,1);
var Vadj_max_pmt = 0;
if(adj_pmt > Vadj_start_pmt) {
   Vadj_max_pmt = adj_pmt;
} else {
   Vadj_max_pmt = Vadj_start_pmt;
}
form.adj_max_pmt.value = "$" + formatNumberDec(Vadj_max_pmt,2,1);

form.io_total_pmts.value = "$" + formatNumberDec(io_accum_pmts,2,1);
form.io_total_int.value = "$" + formatNumberDec(io_accum_int,2,1);
var Vio_max_pmt = 0;
if(io_pmt > Vio_start_pmt) {
   Vio_max_pmt = io_pmt;
} else {
   Vio_max_pmt = Vio_start_pmt;
}
form.io_max_pmt.value = "$" + formatNumberDec(Vio_max_pmt,2,1);

var fix_max_rate = fix_rate;

var adj_max_rate = 0;
if(adj_rate > Vadj_start_rate) {
   adj_max_rate = adj_rate;
} else {
   adj_max_rate = Vadj_start_rate;
}

var io_max_rate = 0;
if(io_rate > Vio_start_rate) {
   io_max_rate = io_rate;
} else {
   io_max_rate = Vio_start_rate;
}

if(report == 1) {

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


var part2 = ("<center><table border=1 cellpadding=2 cellspacing=0 bordercolor='#EEEEEE'><tr bgcolor='silver'><td colspan='4'><font face='arial'><small><b>Comparisons</b></small></font></td><td align='center'><font face='arial'><small><b>Fixed Mortgage</b></small></font></td><td align='center'><font face='arial'><small><b>Fully Amortizing ARM</b></small></font></td><td align='center' colspan='2'><font face='arial'><small><b>Interest Only ARM</b></small></font></td></tr><tr><td colspan=4><font face='arial'><small>Mortgage loan amount:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vprincipal,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vprincipal,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vprincipal,2,1) + "</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Mortgage term:</small></font></td><td align='right'><font face='arial'><small>" + VnumYears + " years</small></font></td><td align='right'><font face='arial'><small>" + VnumYears + " years</small></font></td><td align='right'><font face='arial'><small>" + VnumYears + " years</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Beginning interest rate:</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vfixed_rate,3,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vadj_start_rate,3,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vio_start_rate,3,1) + "%</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Maximum interest rate:</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vfixed_rate,3,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(adj_max_rate,3,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(io_max_rate,3,1) + "%</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Beginning monthly payment:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vfixed_pmt,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vadj_start_pmt,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vio_start_pmt,2,1) + "</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Maximum monthly payment:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vfixed_pmt,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vadj_max_pmt,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vio_max_pmt,2,1) + "</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Interest rate cap:</small></font></td><td align='right'><font face='arial'><small>N/A</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vadj_rate_cap,3,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vio_rate_cap,3,1) + "%</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Expected rate adjustment amount:</small></font></td><td align='right'><font face='arial'><small>N/A</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vadjust_amt,2,1) + "%</small></font></td><td align='right'><font face='arial'><small>" + formatNumberDec(Vadjust_amt,2,1) + "%</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Initial fixed rate period:</small></font></td><td align='right'><font face='arial'><small>N/A</small></font></td><td align='right'><font face='arial'><small>" + Vadj_start_months + " months</small></font></td><td align='right'><font face='arial'><small>" + Vio_start_months + " months</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Total payments:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(fix_accum_pmts,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(adj_accum_pmts,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(io_accum_pmts,2,1) + "</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Total interest:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(fix_accum_int,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(adj_accum_int,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(io_accum_int,2,1) + "</small></font></td></tr><tr><td colspan=4><font face='arial'><small>Ending principal balance:</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(fix_prin,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(adj_prin,2,1) + "</small></font></td><td align='right'><font face='arial'><small>$" + formatNumberDec(Vprincipal,2,1) + "</small></font></td></tr><tr><td colspan=7><center><font face='arial'><b>Schedule of Payments</b></font><br><font face='arial'><small><small>Please allow for slight rounding differences.</small></small></font></center></td></tr><tr bgcolor='silver'><td align='center'><font face='arial'><small><b>Pmt</b></small></font></td><td align='center' colspan='2'><font face='arial'><small><b>Fixed Mortgage</b></small></font></td><td align='center' colspan='2'><font face='arial'><small><b>Fully Amortizing ARM</b></small></font></td><td align='center' colspan='2'><font face='arial'><small><b>Interest Only ARM</b></small></font></td></tr><tr bgcolor='silver'><td align='center'><font face='arial'><small><b>#</b></small></font></td><td align='center'><font face='arial'><small><b>Payment</b></small></font></td><td align='center'><font face='arial'><small><b>Balance</b></small></font></td><td align='center'><font face='arial'><small><b>Payment</b></small></font></td><td align='center'><font face='arial'><small><b>Balance</b></small></font></td><td align='center'><font face='arial'><small><b>Payment</b></small></font></td><td align='center'><font face='arial'><small><b>Balance</b></small></font></td></tr>");



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



var part4 = ("</table><br><center><form method='post'><input type='button' value='Close Window' onClick='window.close()'></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) {

form.fixed_pmt.value = "";
form.fixed_total_pmts.value = "";
form.fixed_total_int.value = "";
form.fixed_max_pmt.value = "";

form.adj_start_pmt.value = "";
form.adj_total_pmts.value = "";
form.adj_total_int.value = "";
form.adj_max_pmt.value = "";

form.io_start_pmt.value = "";
form.io_total_pmts.value = "";
form.io_total_int.value = "";
form.io_max_pmt.value = "";
}