Adding additonal confirmation box 2 chkout

[A-1 Electronics]

I know I am confusing myself. I have found other threds that refer to jscript files and a few others. But nothing that seems to be helping. The checkboxes are in place and worded correctly. As I have stated before, this is a requirement from my merchant processor before they will approve my account. Even a little clue as to where I need to validate the checkbox would be great. I tried looking for where the box for _CONDITIONS_ is confirmed by doing a search in the developers tool kit. That didn't turn up anything. I'll try some more searches.

[A-1 Electronics]

I am thinking it has to be in a jscript file somewhere.

[Ajeh]

Add this:
define('DISPLAY_CONDITIONS_ON_CHECKOUT', 'true');

Right above where you have:

if (DISPLAY_CONDITIONS_ON_CHECKOUT == 'true') {
  if (!isset($_POST['conditions']) || ($_POST['conditions'] != '1')) {
    $messageStack->add_session('checkout_payment', ERROR_CONDITIONS_NOT_ACCEPTED, 'error');
  }
} 

Does it start to work?

[A-1 Electronics]

Nope. That didn't work. I am still getting the same results. I can select the box for confirming the terms and conditions and not the other two boxes. And it will still allow me to continue. If I do not select the terms box I receive the error.

P.S.
Thank you for all your help. Please excuse my frustrations. I am truely tring to understand.

[A-1 Electronics]

I have moded 3 files in order to get this far. The one thing I haven't been able to figure out or locate in any file is how zc checks that the customer has placed a checkmark in the box argeeing to the terms. In the admin - config - regs there is a way to turn this on and off. How indepth would it be add additional regulations to the admin panel?

[A-1 Electronics]

Found this in tpl_checkout_payment_default.php. does this have to do with validating the check box for the terms?

?>
<?php echo $payment_modules->javascript_validation(); ?>
<div class="centerColumn" id="checkoutPayment">
<?php echo zen_draw_form('checkout_payment', zen_href_link(FILENAME_CHECKOUT_CONFIRMATION, '', 'SSL'), 'post', ($flagOnSubmit ? 'onsubmit="return check_form();"' : '')); ?>

[Ajeh]

What is this constant defined as and where:
ERROR_RETURNS_NOT_ACCEPTED