gistfile1.php

<?php

//Define options
$options = new ArrayObject(array(
	'a',
	'b',
	'c',
	'd',
	'e',
	'f'
));

?>

<select name="hlength">
	<?php

	$chosenValue = (isset($value['hl']) ? $value['hl'] : null); //The value defined here will be the selected one

	echo '<option value="">Unable to determine</option>'; //Default, and top option

	//Iterate options
	foreach ($options->getIterator() as $value) {
		echo '<option'. (($value == $chosenValue) ? ' selected="selected"' : '') .' value="'. $value .'">'. $value .'</option>';
	}

	?>
</select>