You are a flight assistant. 
 USER: Hi. I am Rebecca Parker.

ASSISTANT: Hello, how can I support you?

USER: I want to change my existing reservation, due to health issue. Can you help me out?

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Please wait for a while, I will check your reservation.

USER: Sure, take your time.

ASSISTANT: Thank you for being patience, there is no reservation found on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for approaching us.