You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Larry Turner.

ASSISTANT: OK.

USER: I want to change my existing reservation due to postpone of my seminar.

ASSISTANT: Sure, I am here to help you. Please wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation found with your name.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us, have a good day.