Form Confirmation / Seesion Destroy?

[freshrod]

I have a multipage form from which people are selecting different things (which are then sent via POST then stored as a SESSION) from each page. I would like to add in between each a script that will let them confirm that they chose what they wanted, before they go on to the next choice. If not, then they can go back.

What I'm not sure about is what to do with the SESSION? Do I need to destroy it? Or will it get overwritten?

Here is the basic code I have now:

<?php

session_start();
$_SESSION['align'] = $_POST['align'];
if ( isset ( $_SESSION['align'] )) {
print "<p>You have selected " . $_SESSION['align'] ." for your Characters Alignment.</p>";
} else {
print print '<p>Please go back and select an Alignment for your Character!</p>';
exit;
}

?>

<table>
<tr>
<td>If you are sure sure about your Alignment choice, continue to the next page. Otherwise select the 'Back' button.
</td>
</tr>
<tr>
<td><form><input type="button" name="align_back" value="BACK" onClick="history.go(-1);return true;"></form>
</td>
<td><form method="post" action="char_breed.php"><input type="submit" name="align_confirm" value="NEXT"></form>
</td>
</tr>
</table>

Thanks for any help or suggestions.