You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my reservation due to health problem, can you help me?

ASSISTANT: Sure, I am here to help you? May I know your name?

USER: Myself Helen Davis.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reserved flight under your name in our records.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for reaching us.