function init() { calc.principal.value = ""; calc.interestrate.value = ""; calc.months1.value = ""; calc.payment.value = ""; } // format floating point number to show dollars and cents function currency2str(f) { var str = ""; var pos = 1; if (f < 0) // negative number { f = -f pos = 0; } // extract dollars and cents var dollars = Math.floor(f); var cents = Math.round(100*(f - dollars)); if (cents == 100) { dollars += 1; cents = 0; } if (pos == 0) str += "("; // show as negative if (cents == 0) str += dollars + ".00"; else if (cents < 10) str += dollars + ".0" + cents; else str += dollars + "." + cents; if (pos == 0) str += ")"; // show as negative return str; } // compute the size of a periodic payment to amortize a loan function monthly_payment( p, apr, n ) { var i = apr/1200; var m = p*i*Math.pow((1 + i), n)/(Math.pow((1 + i), n) - 1); return (0.01*Math.ceil(100*m)); // round up } // total interest and payment size for a loan function compute1() { var principal = removeCurrency(calc.principal.value); principal = parseFloat(principal); var int_rate = parseFloat(calc.interestrate.value); var months1 = parseInt(calc.months1.value); months1 *= 12; var payment = monthly_payment( principal, int_rate, months1 ); var interest = parseFloat("0"); if (!principal || !int_rate || !months1) { alert("invalid data"); return; } // compute total interest paid while (principal > 0.0) { var ip = 0.01*Math.round(principal*int_rate/12); principal = principal + ip - payment; interest += ip; } calc.payment.value = currency2str(payment); calc.interest1.value = currency2str(interest); } // interest and principal of each payment in a separate window function listing1() { var principal = removeCurrency(calc.principal.value); principal = parseFloat(principal); var int_rate = parseFloat(calc.interestrate.value); var months1 = parseInt(calc.months1.value); months1 *= 12; var payment = monthly_payment( principal, int_rate, months1 ); var count = parseInt("0"); if (!principal || !int_rate || !months1) { msgWindow=window.open("","msgWindow","toolbar=no,status=no,menubar=yes,scrollbars=yes,width=550,height=400"); msgWindow.document.open(); msgWindow.document.writeln("Invalid Data"); msgWindow.document.writeln(""); msgWindow.document.writeln("Please Enter Valid Data
"); return; } msgWindow=window.open("","msgWindow","toolbar=no,status=no,menubar=yes,scrollbars=yes,width=550,height=400"); msgWindow.document.open(); msgWindow.document.writeln("Principal and interest listing"); msgWindow.document.writeln(""); msgWindow.document.writeln("
"); msgWindow.document.writeln("Creating Amortization Schedule
"); msgWindow.document.writeln("This may take a few moments...

"); msgWindow.document.writeln("Monthly Payment = $" + currency2str(payment)); msgWindow.document.writeln(""); msgWindow.document.writeln(""); while (principal > 0.0) { var ip = 0.01 * Math.round(principal*int_rate/12); if (payment > principal + ip) payment = principal + ip; var pp = payment - ip; var principal = principal + ip - payment; count++; if (count % 2 == 0) { msgWindow.document.write(""); } else { msgWindow.document.write(""); } } msgWindow.document.write("
monthprincipalinterestbalance
"); msgWindow.document.write(count); msgWindow.document.write("" + currency2str(pp)); msgWindow.document.write("" + currency2str(ip)); msgWindow.document.write("" + currency2str(principal)); msgWindow.document.writeln("
"); msgWindow.document.write(count); msgWindow.document.write("" + currency2str(pp)); msgWindow.document.write("" + currency2str(ip)); msgWindow.document.write("" + currency2str(principal)); msgWindow.document.writeln("
"); msgWindow.document.write(""); msgWindow.document.close(); } function removeCurrency( strValue ) { /************************************************ DESCRIPTION: Removes currency formatting from source string. PARAMETERS: strValue - Source string from which currency formatting will be removed; RETURNS: Source string with commas removed. *************************************************/ var objRegExp = /\(/; var strMinus = ''; //check if negative if(objRegExp.test(strValue)){ strMinus = '-'; } objRegExp = /\)|\(|[,]/g; strValue = strValue.replace(objRegExp,''); if(strValue.indexOf('$') >= 0){ strValue = strValue.substring(1, strValue.length); } return strMinus + strValue; } // interest and principal of each payment in a separate window function listing2() { var principal = removeCurrency(fha_calc.mortAmt.value); principal = parseFloat(principal); var int_rate = parseFloat(fha_calc.mortRate.value); var months1 = parseInt(fha_calc.numYears.value); months1 *= 12; var count = parseInt("0"); var payment = monthly_payment( principal, int_rate, months1 ); if (!principal || !int_rate || !months1) { msgWindow=window.open("","msgWindow","toolbar=no,status=no,menubar=yes,scrollbars=yes,width=550,height=400"); msgWindow.document.open(); msgWindow.document.writeln("Invalid Data"); msgWindow.document.writeln(""); msgWindow.document.writeln("Please Enter Valid Data
"); return; } msgWindow=window.open("","msgWindow","toolbar=no,status=no,menubar=yes,scrollbars=yes,width=550,height=400"); msgWindow.document.open(); msgWindow.document.writeln("Principal and interest listing"); msgWindow.document.writeln(""); msgWindow.document.writeln("
"); msgWindow.document.writeln("Creating Amortization Schedule
"); msgWindow.document.writeln("This may take a few moments...

"); msgWindow.document.writeln("Monthly Payment = $" + currency2str(payment)); msgWindow.document.writeln(""); msgWindow.document.writeln(""); while (principal > 0.0) { var ip = 0.01 * Math.round(principal*int_rate/12); if (payment > principal + ip) payment = principal + ip; var pp = payment - ip; var principal = principal + ip - payment; count++; if (count % 2 == 0) { msgWindow.document.write(""); } else { msgWindow.document.write(""); } } msgWindow.document.write("
monthprincipalinterestbalance
"); msgWindow.document.write(count); msgWindow.document.write("" + currency2str(pp)); msgWindow.document.write("" + currency2str(ip)); msgWindow.document.write("" + currency2str(principal)); msgWindow.document.writeln("
"); msgWindow.document.write(count); msgWindow.document.write("" + currency2str(pp)); msgWindow.document.write("" + currency2str(ip)); msgWindow.document.write("" + currency2str(principal)); msgWindow.document.writeln("
"); msgWindow.document.write(""); msgWindow.document.close(); } function rtrim(argvalue) { while (1) { if (argvalue.substring(argvalue.length - 1, argvalue.length) != " ") break; argvalue = argvalue.substring(0, argvalue.length - 1); } return argvalue; } function ltrim(argvalue) { while (1) { if (argvalue.substring(0, 1) != " ") break; argvalue = argvalue.substring(1, argvalue.length); } return argvalue; } // Round a field two (2) decimals function round(number) { return Math.round(number*Math.pow(10,2))/Math.pow(10,2); } function trim(str) { return str.replace(/^\s+/g, '').replace(/\s+$/g, ''); } function count(form) { if (( trim(form.mortAmt.value) != "" && trim(form.numYears.value) != "" && trim(form.propTax.value) != "" && trim(form.debt.value) != "" && trim(form.mortRate.value) != "")) {} else { alert('invalid or missing data'); return; } { var tmp1,tmp2, tmp3, tmp4, tmp5, tmp6 ,tmp7, tmp8, tmp9, tmp10, tmp11, tmp12, tmp13, tmp14, tmp15 tmp1 = removeCurrency(fha_calc.mortAmt.value); tmp1 = parseFloat(tmp1); if (isNaN(tmp1)) tmp1=0; tmp2 = parseFloat(form.numYears.value); if (isNaN(tmp2)) tmp2=0; tmp3 = parseFloat(form.mortRate.value); if (isNaN(tmp3)) tmp3=0; tmp4 = removeCurrency(form.propTax.value); tmp4 = parseFloat(tmp4); if (isNaN(tmp4)) tmp4=0; tmp5 = removeCurrency(form.debt.value); tmp5 = parseFloat(tmp5); if (isNaN(tmp5)) tmp5=0; tmp6 = 0; tmp7 = tmp4/12; tmp8= tmp5/12; tmp9 = tmp3/1200; tmp10= tmp2 * 12; tmp11 = (1 + tmp9); for (i=1; i < tmp10; i++) { tmp11 = tmp11 * (1 + tmp9); } tmp12 = tmp1 * tmp11 * tmp9 / (tmp11 - 1); tmp13 = tmp12 + tmp7 + tmp8; tmp14= (tmp12 + tmp7) / 0.28; tmp15 = tmp13 / 0.35; if (tmp14 > tmp15) { tmp6 = 12 * tmp14; } else { tmp6 = 12 * tmp15; } form.mortPay.value = round(tmp12); form.totalPay.value = round(tmp13); form.reqdSal.value = round(tmp6); } }