//******************************************* //DO NOT REMOVE THIS COPYWRITE INFO! //Auto Loan Rate Comparison Calculator //2003 Daniel C. Peterson ALL RIGHTS RESERVED //Created: 11/12/2003 //Last Modified: 11/12/2003 //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 #:5782-1237-114-1198 //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 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 computeFixedInterestCost(principal, intRate, pmtAmt) { var i = eval(intRate); if(i >= 1) { i /= 100; } i /= 12; var prin = eval(principal); var intPort = 0; var accumInt = 0; var prinPort = 0; var pmtCount = 0; var testForLast = 0; //CYCLES THROUGH EACH PAYMENT OF GIVEN DEBT while(prin > 0) { testForLast = (prin * (1 + i)); if(pmtAmt < testForLast) { intPort = prin * i; accumInt = eval(accumInt) + eval(intPort); prinPort = eval(pmtAmt) - eval(intPort); prin = eval(prin) - eval(prinPort); } else { //DETERMINE FINAL PAYMENT AMOUNT intPort = prin * i; accumInt = eval(accumInt) + eval(intPort); prinPort = prin; prin = 0; } pmtCount = eval(pmtCount) + eval(1); if(pmtCount > 1000 || accumInt > 1000000000) { prin = 0; } } return accumInt; } 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 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(form) { if(form.principal.value.length == 0) { alert("Please enter the amount to be financed."); form.principal.focus(); } else { var Vprin = stripNum(form.principal.value); var term = 0; var rate = 0; var count = 0; var moPmt = 0; var totPrin = 0; var totInt = 0; var totPmts = 0; while(count < 5) { count = count + 1; eval("term = stripNum(form.term_" + count + ".value);"); eval("rate = stripNum(form.rate_" + count + ".value);"); if(rate >= 0 && term > 0) { eval("moPmt = computeMonthlyPayment(Vprin, term, rate);"); eval("form.moPmt_" + count + ".value = \"$\" + formatNumberDec(moPmt,2,1);"); eval("form.totPrin_" + count + ".value = \"$\" + formatNumberDec(Vprin,0,1);"); eval("totInt = computeFixedInterestCost(Vprin, rate, moPmt);"); totInt = Math.round(totInt); eval("form.totInt_" + count + ".value = \"$\" + formatNumberDec(totInt,0,1);"); totPmts = eval(Vprin) + eval(totInt); eval("form.totPmts_" + count + ".value = \"$\" + formatNumberDec(totPmts,0,1);"); } else { eval("form.moPmt_" + count + ".value = \"\";"); eval("form.totPrin_" + count + ".value = \"\";"); eval("form.totInt_" + count + ".value = \"\";"); eval("form.totPmts_" + count + ".value = \"\";"); } } } } function createReport(form) { if(form.principal.value.length == 0) { alert("Please enter the amount of the mortgage."); form.principal.focus(); } else { computeForm(form); var Vprin = stripNum(form.principal.value); var termRows = ""; termRows = ("" + termRows + "Monthly payment:" + form.moPmt_1.value + "" + form.moPmt_2.value + "" + form.moPmt_3.value + "" + form.moPmt_4.value + "" + form.moPmt_5.value + ""); termRows = ("" + termRows + "Principal payments:" + form.totPrin_1.value + "" + form.totPrin_2.value + "" + form.totPrin_3.value + "" + form.totPrin_4.value + "" + form.totPrin_5.value + ""); termRows = ("" + termRows + "Interest payments:" + form.totInt_1.value + "" + form.totInt_2.value + "" + form.totInt_3.value + "" + form.totInt_4.value + "" + form.totInt_5.value + ""); termRows = ("" + termRows + "Total payments:" + form.totPmts_1.value + "" + form.totPmts_2.value + "" + form.totPmts_3.value + "" + form.totPmts_4.value + "" + form.totPmts_5.value + ""); var part1 = ("Auto Loan Rate/Term Comparison" + "

Auto Loan Rate/Term Comparison
"); var part2 = ("
"); var part3 = ("" + termRows + ""); var part4 = ("
Amount Financed: $" + formatNumberDec(Vprin,0,1) + "
Months" + form.term_1.value + "" + form.term_2.value + "" + form.term_3.value + "" + form.term_4.value + "" + form.term_5.value + "
Interest Rate" + form.rate_1.value + "%" + form.rate_2.value + "%" + form.rate_3.value + "%" + form.rate_4.value + "%" + form.rate_5.value + "%

"); 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(); } }