firm

<?php if($contact['id'] == $number['contact_id']): ?>
<option value="phone-number">
     <?php echo $number['phone_number'];?>
</option>
<?php endif;?>

<?
$arr_numbers =  array();
foreach ($contacts as $contact)
{
   foreach ($numbers as $number)
   {
    if($contact['id'] == $number['contact_id']) $arr_numbers[]= $number['phone_number'];
   }
}
?>

<?php if(count($arr_numbers ) > 0): ?>
<select phones="phones">   
                <?php foreach ($arr_numbers as $number):?>
                    <option value="phone-number">
                        <?=$number['phone_number'];?>
                </option>
                <?php endforeach;?> 
</select>
<?php endif;?>