calling web service in WCF layer

Hi:
My project involves the implementation of four Web services: Web portal, extranet, CRM and Billing, and the implementation of a WCF layer which need to call methods from these services.

In wcf project i have method CreationCustomer() . In this method, i should do a test of origin of creation (CRM,Extranet or others services) and then when i know that the creation for example is done by CRM i call the creation method in CRM service.

but what I have to do in the test to know that creation is made by CRM or extranet or other services????

pleaaaaaaase any body have an idea :(((((((((((((((((((((((((((((((