You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Shirley Barker.

ASSISTANT: How may I assist you?

USER: I am planning to change an exiting reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Wait a moment please, let me check with that.

USER: Sure.

ASSISTANT: Shirley Barker, we haven't found any reservation under your name in our database.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.