how to use set_select on a form to show the old value?

HTML before output:

Code:

<form action="http://ci-demo/" method="post" accept-charset="utf-8">
                <select name="myselect">
                    <option value="one" selected="selected">One</option>
                    <option value="two">Two</option>
                    <option value="three">Three</option>
                </select>
                <button type="submit">Send</button>
</form>

HTML after output:

Code:

<form action="http://ci-demo/" method="post" accept-charset="utf-8">
                <select name="myselect">
                    <option value="one">One</option>
                    <option value="two" selected="selected">Two</option>
                    <option value="three">Three</option>
                </select>
                <button type="submit">Send</button>
</form>

Run code: 

PHP Code:

<?= form_open() ?>
                <select name="myselect">
                    <option value="one" <?= set_select('myselect', 'one', true) ?>>One</option>
                    <option value="two" <?= set_select('myselect', 'two') ?>>Two</option>
                    <option value="three" <?= set_select('myselect', 'three') ?>>Three</option>
                </select>
                <button type="submit">Send</button>
<?= form_close() ?>

Check value dump($booking->status);

Simple CI 4 project for beginners codeigniter-expenses ( topic )