I've been fighting this problem quite some time, and still haven't found the solution. 

See the attached picture.

When I check of the "Contact person = costumer" box, I wan't the application to fill out the fields "Contact" and "Mobile". The "Contact" field is easy, cause it's equal to the "Costumer" field, but how do I get my app to fetch the phone number from the CRM?

Hope you can help me,

Kind regards, Mads R. Svendsen