";
var shBeginTable2 =
"";
var shBeginRow = "";
var shEndRow = "
";
var shCell1 = "%s | ";
var shCell2 = "%s | ";
var shCell3 = "%s | ";
var shCell4 = "%s"
+ " | ";
var shCell5 = "%s"
+ " | ";
var shEndPage = "Back"
function EmitRow1(s1, s2)
{
Emit(shBeginRow);
Emit1(shCell1, s1);
Emit1(shCell2, s2);
Emit(shEndRow);
}
function EmitRow2(s1, s2, sx, s3, s4, s5)
{
Emit(shBeginRow);
Emit1(shCell3, s1);
Emit1(shCell3, s2);
if (bPrincipal)
Emit1(shCell3, sx);
Emit1(shCell3, s3);
Emit1(shCell3, s4);
Emit1(shCell3, s5);
Emit(shEndRow);
}
function EmitRow3(s1, s2, sx, s3, s4, s5)
{
Emit(shBeginRow);
Emit1(shCell2, s1);
Emit1(shCell2, s2);
if (bPrincipal)
Emit1(shCell4, Format(sx, 0, 2));
Emit1(shCell4, Format(s3, 0, 2));
Emit1(shCell4, Format(s4, 0, 2));
Emit1(shCell4, Format(s5, 0, 2));
Emit(shEndRow);
}
function EmitRow4(s1, s2, sx, s3, s4, s5)
{
Emit(shBeginRow);
Emit1(shCell1, s1);
Emit1(shCell1, s2);
if (bPrincipal)
Emit1(shCell5, Format(sx, 0, 2));
Emit1(shCell5, Format(s3, 0, 2));
Emit1(shCell5, Format(s4, 0, 2));
Emit1(shCell5, Format(s5, 0, 2));
Emit(shEndRow);
}
function EmitRow5(s1, s2)
{
Emit(shBeginRow);
Emit1(shCell1,s1);
Emit1(shCell4, s2);
Emit(shEndRow);
}
function Execute(oForm)
{
var iError = 0;
var nPrincipal, nInputInterest, iYears, iStartMonth;
var iStartYear, bShowFull, iPrepayMethod, nPrepay, iPrepayPeriod;
var iPrepayUse, iPpy;
if ( (nPrincipal = Validate(oForm.apph0001.value, 0)) == nErrorNumber)
iError = 100;
else if ( (nInputInterest = Validate(oForm.apph0002.value, 0))
== nErrorNumber)
iError = 110;
else if ( (iYears = Validate(oForm.apph0003.value, 1)) == nErrorNumber)
iError = 120;
else if ( (iStartMonth = parseInt(oForm.apph0004.options[
oForm.apph0004.selectedIndex].value)) == 0)
iError = 130;
else if ( (iStartYear = Validate(oForm.apph0005.value, 1))
== nErrorNumber)
iError = 140;
else
{
bShowFull = parseInt(oForm.apph0006.options[oForm.apph0006.selectedIndex].value);
// var iPpy = parseInt(oForm.apph0007.value);
iPpy = 12;
iPrepayMethod = parseInt(oForm.apph0008.options[oForm.apph0008.selectedIndex].value);
if ( (nPrepay = Validate(oForm.apph0009.value, 0)) == nErrorNumber)
iError = 150;
else if ( (iPrepayPeriod = Validate(oForm.apph0010.value, 1))
== nErrorNumber)
iError = 160;
// var iPrepayUse = parseInt(oForm.apph0011.value);
var iPrepayUse = 1;
// 0=reduce payment; 1=pay off early
}
var nHalfPrepay = Round(nPrepay/2, 2);
var iMonths = 12 * iYears;
var iPeriods = iPpy * iYears;
var nPercent = nInputInterest / iPpy / 100;
var nPrepayPv = 0, nPayment = 0;
var bSemaPrepay = 0, bPeriodPrepay = 0;
var bAnnPrepay = 0, bSinglePrepay = 0;
var sSummPayment = "N/A", sSummInterest1 = "N/A",
sSummInterest2 = "N/A", sSummInterest3 = "N/A",
sSummYrsReduction = "N/A", sSummAvgInterest1 = "N/A",
sSummAvgInterest2 = "N/A", sSummAvgInterest3 = "N/A";
var iReducedMonths = 0;
// alert(iError);
if (!iError)
{
switch (iPrepayMethod)
{
case 0: // None: No Prepayments
default:
break;
case 1: // Monthly: Pre-pay a set amount each month
case 2: // Biweekly: Pre-pay a set amount every two
// weeks
bPeriodPrepay = 1;
break;
case 3: // Semiannually: Prepay a set amount every 6 months
bSemaPrepay = 1;
break;
case 4: // Annually: Pre-pay a set amount once each year
// bSemmPrepay = 1;
bAnnPrepay = 1;
break;
case 5: // One Time: Pre-pay one set amount
// after a given # of months
bSinglePrepay = 1;
break;
}
var sMessage = "";
if (nPrincipal == 0)
sMessage = "Please enter a principal loan balance";
else if (nPrincipal < 0)
sMessage = "Principal loan balance must be positive";
else if (nPercent == 0)
sMessage = "Please enter an interest rate";
else if (nPercent < 0)
sMessage = "Interest rate must be positive";
else if (iYears == 0)
sMessage = "Please enter an amortization length";
else if (iYears < 0)
sMessage = "Amortization length must be positive";
else if (iYears > 30)
sMessage = "Amortization length must be 30 years or less";
else if (iStartYear == 0)
sMessage = "Please enter a starting year";
else if (iPrepayMethod && !nPrepay)
sMessage = "Please enter a pre-payment amount";
else if (nPrepay && iPrepayMethod == 0)
sMessage = "Please select a pre-payment method";
else if (nPrepay < 0)
sMessage = "Pre-payment amount must be positive";
else if (bSinglePrepay &&
(iPrepayPeriod <= 0 || iPrepayPeriod > iPeriods))
sMessage = "Please enter the appropriate month # for "
+ "one-time pre-payment";
else if (!bSinglePrepay && iPrepayPeriod)
sMessage = "The one-time pre-payment field should "
+ "be left blank unless you have selected the "
+ "one-time pre-payment method above";
if (sMessage != "")
{
iError = 170;
alert(sMessage);
}
}
if (!iError)
{
if (bPeriodPrepay)
nPrepayPv += PresentValue(nPrepay, nPercent, iPeriods);
// if (bSemmPrepay)
// nPrepayPv += PresentValue(nHalfPrepay, nPercent/2,
// iPeriods*2);
if (bSemaPrepay)
nPrepayPv += SparsePresentValue(nPrepay, nPercent,
iPpy/2, iPeriods);
if (bAnnPrepay)
nPrepayPv += SparsePresentValue(nPrepay, nPercent,
iPpy, iPeriods);
if (bSinglePrepay)
nPrepayPv += SparsePresentValue(nPrepay, nPercent,
iPrepayPeriod, iPrepayPeriod);
nPayment = (iPrepayUse ? nPrincipal : (nPrincipal - nPrepayPv))
/ PresentValue(1, nPercent, iPeriods);
nPayment = Round(nPayment + .005, 2);
sSummPayment = nPayment;
if (nPrepayPv > 0)
{
var nFraction = 0;
var nBalance = nPrincipal;
var nInterest, nReduction;
sSummInterest1 = 0;
for (var iK = 1; iK <= iMonths; ++iK)
{
nInterest = nBalance * nPercent + nFraction;
nFraction = nInterest - Round(nInterest,2);
nInterest = Round(nInterest,2);
if (nPayment > nBalance + nInterest)
nPayment = nBalance + nInterest;
nReduction = nPayment - nInterest;
nBalance -= nReduction;
sSummInterest1 += nInterest;
}
nPayment = sSummPayment;
sSummAvgInterest1 = sSummInterest1 / iMonths;
iReducedMonths = Math.round(Math.log(
1-nPercent*nPrincipal / nPayment)
/ Math.log(1 - nPercent));
sSummYrsReduction = (iMonths - iReducedMonths) / 12;
sSummInterest2 = iReducedMonths * nPayment - nPrincipal
+ nPrepayPv;
sSummInterest3 = sSummInterest1 - sSummInterest2;
// sSummAvgInterest2 = sSummInterest3 / iReducedMonths;
sSummAvgInterest2 = sSummInterest2 / iMonths;
sSummAvgInterest3 = sSummAvgInterest1 - sSummAvgInterest2;
sSummYrsReduction = Format(sSummYrsReduction, 0, 1);
sSummInterest2 = DollarFormat(sSummInterest2, 0, 2);
sSummInterest3 = DollarFormat(sSummInterest3, 0, 2);
sSummAvgInterest2 = DollarFormat(sSummAvgInterest2, 0, 2);
sSummAvgInterest3 = DollarFormat(sSummAvgInterest3, 0, 2);
}
}
if (!iError)
{
Emit1(shStart, "
Amortization Schedule Results<\/span><\/center>");
Emit1(shHeading1, "Amortization Schedule Results<\/span><\/center>");
Emit1(shHeading2, "MORTGAGE INFORMATION<\/span>");
Emit(shBeginTable2);
EmitRow1("Principal", DollarFormat(nPrincipal, 0, 2));
EmitRow1("Interest Rate", nInputInterest + " %");
EmitRow1("Amortization Period", iYears + " Years");
EmitRow1("Starting month", Mmm(iStartMonth));
EmitRow1("Starting year", iStartYear);
EmitRow1("Monthly Mortgage Payment", DollarFormat(nPayment, 0, 2));
if (nPrepayPv)
EmitRow1(
bPeriodPrepay ? "Monthly Pre-Payment Amount"
: bSemaPrepay ? "Semiannual Pre-Payment Amount"
: bAnnPrepay ? "Annual Pre-Payment Amount"
: "One-Time Pre-Payment",
DollarFormat(nPrepay, 0, 2)
+ (bSinglePrepay ? (" paid after month "
+ iPrepayPeriod) : ""));
// if (bDebug)
// EmitRow1("nPrepayPv*", DollarFormat(nPrepayPv, 0, 2));
Emit(shEndTable);
}
if (!iError && bDebug)
{
Emit1(shHeading2, "ESTIMATED SUMMARY");
Emit(shBeginTable2);
EmitRow1("Reduced Months", iReducedMonths);
EmitRow1("Prepayment Present Value",
DollarFormat(nPrepayPv, 0, 2));
EmitRow1("Monthly Payment", DollarFormat(sSummPayment, 0, 2));
EmitRow1("Total Interest Without Pre-Payment",
DollarFormat(sSummInterest1, 0, 2));
EmitRow1("Total Interest With Pre-Payment (if applicable)",
sSummInterest2);
EmitRow1("Total Interest Saved", sSummInterest3);
EmitRow1("Total Reduction in Years of Loan Length "
+ "(if applicable)", sSummYrsReduction);
if (bDisplayAverageInterest)
{
EmitRow1("Average Interest Per Month Without Pre-Payment",
DollarFormat(sSummAvgInterest1, 0, 2));
EmitRow1("Average Interest Per Month With Pre-Payment (if applicable)",
sSummAvgInterest2);
EmitRow1("Average Interest Per Month Saved (if applicable)",
sSummAvgInterest3);
}
Emit(shEndTable);
}
if (!iError)
{
if (nPrepayPv == 0)
{
sSummInterest1 = 0;
sSummAvgInterest1 = 0;
}
else
{
sSummInterest2 = sSummInterest3 = 0;
sSummAvgInterest2 = sSummAvgInterest3 = 0;
}
Emit1(shHeading2, "AMORTIZATION SCHEDULE<\/span>");
Emit(sNl + sNl + sNl);
Emit(shBeginTable2);
EmitRow2("Year", "Month", "Payment", "Principal",
"Interest", "Balance");
var iK, iN;
var nBalance = nPrincipal;
var iMonth = iStartMonth, iYear = iStartYear;
var nInterest, nReduction;
var nPrepayment;
var nSavedInterest = 0;
// if (bSemmPrepay)
// nSavedInterest = PresentValue(nHalfPrepay, -nPercent/2, 1);
var bDetail = true, bEoy = 0, iStopK = 0;
var sCol1, sCol2;
var nYrPayment = 0, nYrPrincipal = 0, nYrInterest = 0;
var nFraction = 0;
for (var iK = 1; !iError && !iStopK && iK <= iPeriods; ++iK)
{
if (iPpy != 26)
{
sCol1 = iYear;
sCol2 = Mmm(iMonth);
}
else
{
sCol1 = "Year # " + Math.floor((iK + iPpy - 1)/iPpy);
sCol2 = "Pmt # " + ((iK-1) % iPpy + 1);
}
nInterest = nBalance * nPercent - nSavedInterest + nFraction;
nFraction = nInterest - Round(nInterest,2);
nInterest = Round(nInterest,2);
nYrInterest += nInterest;
nPrepayment = 0;
if (bPeriodPrepay || (bAnnPrepay && iK % iPpy == 0)
|| (bSinglePrepay && iK == iPrepayPeriod))
nPrepayment += nPrepay;
// if (bSemmPrepay)
// nPrepayment += nHalfPrepay;
if (bSemaPrepay && (iK % (iPpy/2) == 0))
nPrepayment += nPrepay;
if (nPayment > nBalance + nInterest - nPrepayment)
{
nPrepayment = nBalance + nInterest - nPayment;
if (nPrepayment < 0)
{
nPayment += nPrepayment;
nPrepayment = 0;
}
}
nYrPayment += nPayment + nPrepayment;
nReduction = nPayment - nInterest;
nBalance -= nReduction;
if (bDetail)
EmitRow3(sCol1, sCol2,
nPayment, nReduction, nInterest, nBalance);
if (nPrepayPv == 0)
sSummInterest1 += nInterest;
else
sSummInterest2 += nInterest;
nBalance -= nPrepayment;
if (bDetail && nPrepayment != 0)
EmitRow3(sCol1, sCol2 + " Prepay",
nPrepayment, nPrepayment, 0, nBalance);
if (Round(nBalance,2) == 0)
{
nBalance = 0;
iStopK = iK;
}
if (bEoy || iK == iPeriods || iStopK)
{
nYrPrincipal = nYrPayment - nYrInterest;
EmitRow4(sCol1, "TOTALS",
nYrPayment, nYrPrincipal, nYrInterest, nBalance);
nYrPrincipal = nYrPayment = nYrInterest = 0;
}
if (iPpy == 26)
{
bEoy = (iK % 26 == 25);
bDetail = (iK > 26);
}
else
{
bEoy = 0;
if (iPpy == 12 || iK % 2 == 0)
if (++iMonth > 12)
{
iMonth = 1;
++iYear;
bDetail = (iK < 3 * iPpy / 4);
// alert(iK + "/" + (3 * iPpy / 4) + "/" + bDetail);
}
if (iMonth == 12 && (iPpy == 12 || iK % 2 == 1))
bEoy = 1;
}
if (bShowFull || bDebug)
bDetail = true;
}
Emit(shEndTable);
}
// alert(sOut);
if (!iError)
{
if (nPrepayPv == 0)
{
sSummAvgInterest1 = sSummInterest1 / iMonths;
// sSummAvgInterest1 = DollarFormat(sSummInterest1 / iMonths,
// 0, 2);
// sSummInterest1 = DollarFormat(sSummInterest1, 0, 2);
}
else
{
sSummYrsReduction = Format((iMonths - iStopK)/12, 0, 1);
sSummAvgInterest2 = sSummInterest2 / iMonths;
sSummInterest3 = sSummInterest1 - sSummInterest2;
sSummAvgInterest3 = sSummAvgInterest1 - sSummAvgInterest2;
sSummInterest2 = DollarFormat(sSummInterest2 , 0, 2);
sSummAvgInterest2 = DollarFormat(sSummAvgInterest2, 0, 2);
sSummInterest3 = DollarFormat(sSummInterest3 , 0, 2);
sSummAvgInterest3 = DollarFormat(sSummAvgInterest3, 0, 2);
}
sSummPayment = DollarFormat(sSummPayment, 0, 2);
sSummInterest1 = DollarFormat(sSummInterest1, 0, 2);
sSummAvgInterest1 = DollarFormat(sSummAvgInterest1, 0, 2);
Emit1(shHeading2, "SUMMARY<\/span>");
Emit(shBeginTable2);
EmitRow5("Monthly Payment", sSummPayment);
EmitRow5("Total Interest Without Pre-Payment",
sSummInterest1);
EmitRow5("Total Interest With Pre-Payment (if applicable)",
sSummInterest2);
EmitRow5("Total Interest Saved (if applicable)", sSummInterest3);
EmitRow5("Total Reduction in Years of Loan Length "
+ "(if applicable)", sSummYrsReduction);
if (bDisplayAverageInterest)
{
EmitRow5("Average Interest Per Month Without Pre-Payment",
sSummAvgInterest1);
EmitRow5("Average Interest Per Month With "
+ "Pre-Payment (if applicable)",
sSummAvgInterest2);
EmitRow5("Average Interest Per Month Saved (if applicable)",
sSummAvgInterest3);
}
Emit(shEndTable);
Emit(shEndPage);
}
if (!iError)
{
// document.open();
document.write(sOut);
document.close();
}
}
function Emit(sStr) { sOut += sStr + sNl ; }
function Emit1(sStr, s1)
{
var iK;
if ( (iK = sStr.indexOf(sSub)) >= 0)
sStr = sStr.substring(0, iK) + s1
+ sStr.substring(iK + sSub.length);
Emit(sStr);
}
function Emitx(sStr, sSubs)
{
var iK, iL, iPos1 = 0, iPos2 = 0;
while ( (iK = sStr.indexOf(iPos1, sSub)) >= 0)
{
if ( (iL = eSubs.indexOf(iPos2, sSep)) < 0)
iL = eSubs.length();
sStr = sStr.substring(0, iK)
+ sSubs.substring(iPos1, iL)
+ sStr.substring(iK + sSub.length());
iPos1 = iK + sSub.length();
if ( (iPos2 = iL + eSep.length()) > sSubs.length())
iPos2 = sSubs.length();
}
Emit(sStr);
}
var sBlanks = " "
+ " ";
var sDashes = "---------------------------------------------"
+ "-----------------------------------------";
var nPowers = [
0.0000000000000001,
0.000000000000001,
0.00000000000001,
0.0000000000001,
0.000000000001,
0.00000000001,
0.0000000001,
0.000000001,
0.00000001,
0.0000001,
0.000001,
0.00001,
0.0001,
0.001,
0.01,
0.1,
1.,
10.,
100.,
1000.,
10000.,
100000.,
1000000.,
10000000.,
100000000.,
1000000000.,
10000000000.];
function Power(n)
{
return nPowers[n+16];
}
var sMonths = ["January", "February", "March", "April", "May",
"June", "July", "August", "September", "October",
"November", "December"];
function Mmm(iK) { if (!(iK >= 1 && iK <= 12)) return "MMM" + iK;
return sMonths[iK-1].substring(0, 3); }
function ExpN(nX, iN) // compute x ** n, where n is integral
{
var nResult = 1;
var bSign = 0;
if (iN < 0)
{
bSign = 1;
iN = -iN;
}
while (iN > 0)
{
if (iN & 1)
nResult *= nX;
nX *= nX;
iN >>= 1;
}
if (bSign)
nResult = 1 / nResult;
return nResult;
}
function PresentValue(nPayment, nPercent, iNumPeriods)
{
var nAmount = (Math.abs(nPercent) > 1e-20)
? nPayment * (1 - ExpN(1 + nPercent, -iNumPeriods))
/ nPercent
: nPayment * iNumPeriods;
return nAmount;
}
function SparsePresentValue(nPayment, nPercent, iInterval, iNumPeriods)
{
var nAmount = (Math.abs(nPercent) > 1e-20)
? nPayment * (1 - ExpN(1 + nPercent, -iNumPeriods))
/ (ExpN(1 + nPercent, iInterval) - 1)
: nPayment * iNumPeriods;
return nAmount;
}
function Round(nVal, iD)
{
var iSign = 1;
if (nVal < 0)
{
nVal = - nVal;
iSign = -1;
}
var iInt = Math.round(nVal);
if (iD > 0)
iInt = Math.floor(nVal);
var nFp = nVal - iInt;
// alert ('iInt, nFp = ' + iInt + ", " + nFp);
if (iD > 0)
nFp = Math.round(nFp * Power(iD)) / Power(iD);
nVal = iSign * (iInt + nFp);
return nVal;
}
function Validate(sVal, bInt)
{
var sMessage = "";
var bDot = 0, bE = 0, iState = 0;
var sCh, iK;
var bInvalid = 0;
var nValue = bInt ? parseInt(sVal) : parseFloat(sVal);
for (iK = 0; sMessage == "" && iK < sVal.length; ++iK)
{
sCh = sVal.charAt(iK);
if (sCh == " ")
{
if (iState > 0)
iState = 9;
}
else
{
if (iState == 9)
sMessage = "Number '" + sVal + "' has an embedded blank";
else if (sCh == '.' && !bInt)
{
if (bDot || bE)
bInvalid = 1;
else
bDot = 1;
}
else if ((sCh == 'e' || sCh == 'E') && !bInt)
{
if (bE)
bInvalid = 1;
else
{
bE = 1;
iState = 6;
}
}
else if (sCh == '+' || sCh == '-')
{
if (iState == 0 || iState == 6)
++iState;
else
sMessage = "Number '" + sVal + "' contains a sign "
+ "in an illegal position"
}
else if (sCh >= '0' && sCh <= '9')
{
if (iState == 1 || iState == 7)
++iState;
else if (iState == 0 || iState == 6)
iState += 2;
}
else
bInvalid = 1;
}
if (bInvalid)
sMessage = "Number '" + sVal + "' contains"
+ " invalid non-numeric character(s)";
}
if (sMessage == "")
if (iState == 1 || iState == 6 || iState == 7)
sMessage = "Illegal number: " + sVal;
else if (iState == 0)
nValue = 0;
if (sMessage != "")
{
alert(sMessage);
nValue = nErrorNumber;
}
return nValue
}
// DollarFormat -- could be jazzed up to produce "CR" or "DB"
function DollarFormat(nVal, iW, iD)
{
return GenFmt(nVal, iW, iD, 1);
}
function Format(nVal, iW, iD)
{
return GenFmt(nVal, iW, iD, 0);
}
function GenFmt(nVal, iW, iD, bDollar) // format val into w chars,
// d digs after decimal point
{
var sOut = "";
var iSign = 0;
nVal = Round(nVal, iD);
if (nVal < 0)
{
nVal = - nVal;
iSign = 1;
}
var iInt = Math.round(nVal);
if (iD > 0)
iInt = Math.floor(nVal);
var nFp = nVal - iInt;
var iDigs = 1;
if (iInt > 9)
iDigs = Math.floor(Math.log(iInt+.1)/Math.log(10)) + 1;
var iLeft = iW - iSign - (bDollar ? 1 : 0);
if (iD > 0)
iLeft -= iD + 1;
if (iLeft > iDigs)
sOut += sBlanks.substring(0, iLeft - iDigs);
if (iSign)
sOut += '-';
if (bDollar)
sOut += '$';
sOut += iInt;
if (iD > 0)
{
nFp = Math.round((1 + nFp) * Power(iD));
sOut += '.' + String(nFp).substring(1);
}
return sOut;
}
function PrepadString(sStr, iW)
{
if (sStr.length < iW)
sStr = sBlanks.substring(0, iW - sStr.length) + sStr;
return sStr;
}
function CenterString(sStr, iW)
{
var iBlanks = iW - sStr.length;
if (iBlanks > 0)
sStr = sBlanks.substring(0, Math.floor(iBlanks/2)) + sStr
+ sBlanks.substring(0, iBlanks - Math.floor(iBlanks/2));
return sStr;
}