You are a flight assistant. 
 USER: Hello, I'm Linda Brown.

ASSISTANT: Hello Linda, how may I serve you?

USER: I would like to change my existing reservation, can you please help me out?

ASSISTANT: Sure, please give me a moment to check the booking history.

USER: Sure.

ASSISTANT: Sorry Linda, there is no reservation found on this name.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us, happy to serve you anytime.