You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation which is done recently due to some health issues, can you please help me in this?

ASSISTANT: Sure, I am here to help you for this. May I know your name please?

USER: Sure, my name is Brandon Young.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry for inconvenience, no reservation is found under your name to change.

USER: Ok, no problem.

ASSISTANT: Thank you very much for approaching our agency.

USER: Anyways, thank you for your service.

ASSISTANT: You are welcome.