php ....

I need Help I Need to Modify this application so it uses a persistent session to save the last values entered by the user for 5 minutes.

At the top of the file (before the DOCTYPE html line) you will need to add a section of code which checks to see if a session id exists. If it does not, the code you add (which will be similar to the example on page 359) will need to start a session.

After the above code (and before the DOCTYPE html line) you will need to add a section of code which checks to see if any of the (3) inputs (amount, rate, & years) already exist in $_SESSION[ ]. If they do, you will need to set the initial values for the form fields to those values.

In display_results.php:

At the top of the file you will need to make sure you start the session (see page 358).

After the input field values (amount, rate, & years) are error checked, you will need to store the values in the session (see pp. 360-361)

Remember to display the day/time when your calculation was performed.

My code for the original assignment before its modified to a persistent session.

index.php-->

//set default value of variables for initial page load

if (!isset($investment)) { $investment = ''; }

if (!isset($interest_rate)) { $interest_rate = ''; }

if (!isset($years)) { $years = ''; }

?>

Future Value Calculator

Future Value Calculator

Investment Amount:

value="

">

Yearly Interest Rate:

value="">

Number of Years:

value="">

display_results.php-->

// get the data from the form

$investment = filter_input(INPUT_POST, 'investment',

FILTER_VALIDATE_FLOAT);

$interest_rate = filter_input(INPUT_POST, 'interest_rate',

FILTER_VALIDATE_FLOAT);

$years = filter_input(INPUT_POST, 'years',

FILTER_VALIDATE_INT);

// validate investment

if ($investment === FALSE ) {

$error_message = 'Investment must be a valid number.';

} else if ( $investment <= 0 ) {

$error_message = 'Investment must be greater than zero.';

// validate interest rate

} else if ( $interest_rate === FALSE ) {

$error_message = 'Interest rate must be a valid number.';

} else if ( $interest_rate <= 0 ) {

$error_message = 'Interest rate must be greater than zero.';

// validate years

} else if ( $years === FALSE ) {

$error_message = 'Years must be a valid whole number.';

} else if ( $years <= 0 ) {

$error_message = 'Years must be greater than zero.';

} else if ( $years > 30 ) {

$error_message = 'Years must be less than 31.';

// set error message to empty string if no invalid entries

} else {

$error_message = '';

}

// if an error message exists, go to the index page

if ($error_message != '') {

include('index.php');

exit();

}

// calculate the future value

$future_value = $investment;

for ($i = 1; $i <= $years; $i++) {

$future_value += $future_value * $interest_rate * .01;

}

// apply currency and percent formatting

$investment_f = '$'.number_format($investment, 2);

$yearly_rate_f = $interest_rate.'%';

$future_value_f = '$'.number_format($future_value, 2);

?>

Future Value Calculator

Future Value Calculator

Investment Amount:

Yearly Interest Rate:

Number of Years:

Future Value:

This calculation was done on echo "" . date("m/d/Y") . "

";

?> at date_default_timezone_set("America/New_York");

echo " " . date("h:i:sa");

?>.

main.css-->

body {

font-family: Arial, Helvetica, sans-serif;

}

main {

display: block;

width: 450px;

margin: 0 auto;

padding: 1em;

background: white;

border: 2px solid navy;

}

h1 {

margin-top: 0;

color: navy;

}

label {

width: 10em;

float: left;

padding-right: 1em;

padding-bottom: .5em;

}

#data input {

float: left;

width: 15em;

margin-bottom: .5em;

}

#buttons input {

float: left;

margin-bottom: .5em;

}

br {

clear: left;

}

.error {

color: red;

font-weight: bold;

}