You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am planning to change an existing reservation, due to health issue. Can you please help me out?

ASSISTANT: Sure, I am here to help you. Please provide your name.

USER: Thank you, my name is Donna Lewis.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your time, No reservation was found on your name.

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

ASSISTANT: Thank you for choosing us.