Hello, I'm kind of new to programming in PHP. I'm trying to do a retirement calculator and I have it basicly completed. But I keep getting warnings about division by zero. I tried to get this to work by making If statements so that if the certain optional variable is 0 then a formula without that variable will be executed. I'm getting very confused. The goal of the script is to get $cf, $s, $fv, $ar, and $da; which is then echoed in an html template. If you can help, I would greatly appreciate it! Division by zero errors happen on lines 93, 94, 94, 103, 141, 151, 151. Below is the entire snippit of code minus the html template. [code] <? if (($_POST[email] == "") || ($_POST[contact] == "")) { header('location: rrsp.html'); exit; } //Determine income frequency $e = 1; if ($_post[incomefreq] = "Annually") { $e = 1; } if ($_post[incomefreq] = "Semi-Annually") { $e = 2; } if ($_post[incomefreq] = "Quarterly") { $e = 4; } if ($_post[incomefreq] = "Monthly") { $e = 12; } if ($_post[incomefreq] = "Weekly") { $e = 52; } if ($_post[incomefreq] = "Bi-Weekly") { $e = 26; } //determine deposit frequency if ($_post[depositfreq] = "Annually") { $df = 1; } if ($_post[depositfreq] = "Semi-Annually") { $df = 2; } if ($_post[depositfreq] = "Quarterly") { $df = 4; } if ($_post[depositfreq] = "Monthly") { $df = 12; } if ($_post[depositfreq] = "Weekly") { $df = 52; } if ($_post[depositfreq] = "Bi-Weekly") { $df = 26; } //Put all Input POSTS into variables if ($_POST[investrate] = 0) { $r = 0; } else { $r = ($_POST[investrate] / 100); } if ($_POST[inflation] = 0) { $i = 0; } else { $i = ($_POST[inflation] / 100); } $c = $_POST[income]; $y = $_POST[yearsto]; $f = $_POST[inflate]; $yl = $_POST[tolast]; $current = $_POST[current]; $fd = $_POST[depositinflate]; //Part 1. The income required in future dollars $cf = $c * (1 + $i)^$y; //where: //cf is the Income required with inflation //c is the income required in todays dollars //i s the inflation rate //y is the years to retirement //Part 2. The savings needed at retirement if ($f = "yes") { if ($r = $i) { $s = $cf * $yl * $e; } if ($r = 0) { $s = $cf * $e * ((1 + $i)^$yl - 1)/$i; } if ($r >= 0) { $e = 1; $a = (1 - ((1 + $r)/$e)^(-e) ) / ($r / $e); $b = (1 - ((1 + $i) / ((1 + $r / $e)^$e))^$yl ) / (1 - (1 + $i) / ((1 + $r / $e)^$e)); $s = $cf * (1 * $r / $e) * $a / $b; } } if ($f = "no") { if ($r = 0) { $s = $cf * $yl * $e; } else { $s = $cf * ((1 - (1 + $r / $e)^(-$yl * $e)) / ($r / $e)) * (1 + $r / $e); } } //Where: //f is if income increases with inflation or not //s is the total savings at retirement //cf is the income required with inflation from Part 1. //yl is the years funds are to last //i is the inflation rate //r is the investment rate //e is the income frequency, such as annual is 1, weekly is 52. //Part 3. Inflated value of registered assets $fv = $current * (1+ $r)^($y); //Where: //fv is the future value of current savings //r is the investment rate //y is the years to retirement //Part 4. Net Amount Required $ar = $s - $fv; //Where: //ar is the net amount required to reach goal //s is the savings at retirement from Part 2 //fv is the future valule of current savings from Part 3 //Part 5. Amount of each deposit $rdf = $r / $df; $kdf = (1 + $rdf)^$df / (1 + $i); if ($fd = "yes") { if ($kdf = 1) { if ($rdf = 0) { $da = $ar / ($y * $df * (1 + $i)^($y)); } else { $da = $ar / ($y * (1 + $i)^($y) * (1 + $rdf) * (1 - (1 + $rdf)^(-$df) ) / $rdf); } } else { $da = $ar / (((($kdf)^($y) - 1) / ( $kdf - 1 )) * $kdf * (1 + $i)^($y) * (1 + $$rdf) * (1 - (1 + $rdf)^(-$df) ) / $rdf); } } if ($fd = "no") { if ($rdf = 0){ $da = $ar / ($y * $df); } else { $da = $ar / ((((1 + $rdf)^($y * $df) - 1) / $rdf) * (1 + $rdf)); } } //Where: //fd is if the deposits increase with inflation or not. //i is the inflation rate //r is the investment rate //da is the deposit amount //ar is the net amount required from Part 4. //y is the years to retirement //rdf is the rate associated with deposit frequency rdf = r / df //kdf = (1+rdf)^df / (1+i) //df is the deposit frequemcy such as annually is 1, weekly is 52. ?> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> <title>canzo</title> <style fprolloverstyle>A:hover {color: #71552B} </style> </head> <body style="font-family: Verdana; font-size: 10pt; color: #000000" link="#005BA6" vlink="#CC6600" alink="#71552B" bgcolor="#FFFFFF"> <table border="0" width="100%" id="table7" cellspacing="0" cellpadding="0"> <tr> <td>Thank you for completing the RRSP Calculator with canzo! You have been e-mailed the results to <$email></td> </tr> <tr> <td>Income Required in Future Dollars = <? echo "$cf"; ?></td> </tr> <tr> <td>The Savings Needed at Retirement = <? echo "$s"; ?></td> </tr> <tr> <td>Inflated Value of Registered Assets = <? echo "$fv"; ?> </td> </tr> <tr> <td height="18">Net Amount Required = <? echo "$ar"; ?></td> </tr> <tr> <td height="12">Amount of Each Deposit <? echo "$dfpost"; ?> = <? echo "$da"; ?></td> </tr> <tr> <td height="11"><br> If you have any questions, please contact us!</td> </tr> </table> </body> </html> [/code] Thanks, Mark
