POP-UP SCREEN FOR IPPBX

We provide virtual office services to our client where one of the services offered is dedicated phone number. We have IPPBX and a CRM written in PHP. One feature in the CRM is POP-UP SCREEN;
Process:
- anyone calls our client's dedicated number
- POP-UP screen should appear (taking the information from our client database, giving the receptionist the basic information about the client ie greetings, nature of business, etc)

The POP-UP screen doesn't work after we migrated from Asterisk to Isabelle.