Gabriella's Radius form

Radius

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CODE FOLLOWS

<?php
    include('includes/header.php');

    //code
        error_reporting(E_ALL);     //set error reporting to all

        echo('<h1>Gabriella\'s Radius form</h1>');

        $step = isset($_POST['step']) ? $_POST['step'] : 0;
        $radius = isset($_POST['radius']) ? $_POST['radius'] : '';

    // filter all input taken from the Browser
        $step = htmlentities($step);
        $radius = htmlentities($radius);

        if ($step == 0)     // first time into this form
        {
            ?>

            <form action="radius.php" method="POST">
                <label for="name">Radius</label>
                <input type="text" size="36" id="name" name="radius" value="">
                <br><br>
                <input type="hidden" name="step" value="1">
                <input type="submit" name="submit" value="Submit">
            </form>

            <?php
        } else // else show what the form gathered
        {

            echo('<p>The following is what the form gathered</p>');
            echo('<p>Please note: The POST array has not been scrubbed</p>');
            echo('<p>Thus, it is open to javascript insertion.</p>');
            echo('<pre>');
            print_r($_POST);
            echo('</pre>');

            $diameter = $radius * 2;

            echo("<h3>Diameter = $diameter</h3>");

                // provide a form to try again
                ?>
                <form action="radius.php" method="POST">
                    <input type="hidden" name="step" value="0">
                    <input type="submit" name="submit" value="Try Again">
                </form>

                <?php
        }

        include('includes/footer.php');
  ?>

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