Affidavit of identity for air travel

Hello sir, I want to book tickets for my relatives from delhi. There are total 4 passengers out of them 1 has not valid original photo ID proof. so i consulted the air india airline and they said that an Advocate affidavit with photo attested will be valid and allowed to travel in flight. So, i was wondering what is the format for this kind of affidavit? how do i draft it? as i know only basic format. Please suggest some format or sample. Thanks & Regards