Coupon code valid only if custom field enabled

Hi, we are using Events Booking on our website, www.pipeline.it
we organize and sell Microsoft Courses.

like this:
www.pipeline.it/it/173-moc-10775-adminis...ses/view_schedacorso

I already have customized some parts of event booking to generete a course catalog and so on.

We would now like to offer a discount to customers if they bring their own laptop to follow the course.
I have created a custom checkbox field in the course if this option is avalialbe.

Then I would like to create a disocunt coupon for all courses; this has to be valid for ALL courses but ONLY if this custom option is enabled...

I'm not afraid of editing a bit of code, just direct me where/which files I need to modify

thanks


Is iot possible to do it?

SOLVED

I added a custom field of type "checkbox" , then I edited the controller file at around line 415:


if ($rowCoupon) {
if ($rowCoupon->code =="MyCoupon")
{
$sql = 'SELECT custom_fields FROM #__eb_events WHERE id='.$eventId;
$db->setQuery($sql) ;
$rowEvent = $db->loadObject();
if (strpos($rowEvent->custom_fields, "MyCustomFieldString")>0)
{
$_SESSION = $rowCoupon->id ;
}
else
{$errorCoupon = true ;}
}
else
{
$_SESSION = $rowCoupon->id ;
}
}
else {
$errorCoupon = true ;
}
} else {
unset($_SESSION) ;
}