You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: Sure, may I know your name for the changing process?

USER: Emily Thomas here.

ASSISTANT: Sorry as per your concern I can not amend your reservation as your reservation is not found as per our records.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Welcome, thank you for reaching us.