PHP checkbox/hidden field question

I am executing the follwoing statement as part of a "while" loop. This is part of a form and I wish to pass the name and value of the checkbox as a hidden field only is the checkbox is checked. Can you suggest how I can accomplish this task? <td><input type="checkbox" name="d_c_arr[]" value="<?php echo $db->f("order_id") ?>"></td> Thank You Paul php