my friend has a H1B filed for himself under company A which is a consulting firm who raises petitions on behalf of people like me who wish to get their own visa filed.This is done while he works for company B which means he has already been working for company B while he applied H1b for company A from outside. His H1B got approved and he has the I797 copy . However , he has not attended stamping due to some issues related to company A. Is it possible to transfer it to the company B he has been working ? is there any threat in doing so since H1b picked for another company when he has been working for company B?Please help !!!! on this.Will the company B be able to do?