When a customer is creating a new ticket the To drop down option is selected (Queue) the service drop down is dynamically loaded, all the services are displayed.

My question is how do I display (dynamically load) the services that belong to that particular queue for and example there is an IT support queue, there are 15 (fifteen) services in that queue and an Facilities queue which has 20 (twenty) services and so on. So I want to display only the 15 services that belong to the IT support if I have selected it.

I just want to find out which file interrogates the database as to display the services.