<form action="<?= $PHP_SELF ?>" method="post">
<select name="list[]" size="5" multiple>
<option>one
<option>two
<option>three
<option>four
<option>five
</select><br>
<input type="submit" name="submit" value="submit">
</form>
<?
if (isset ($submit))
{
echo 'You selected:<ul>';
foreach ($list as $value) {echo '<li>' . $value;}
echo '</ul>';
}
?>