You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change an existing reservation due to sudden change in my trip.

ASSISTANT: Ok.

USER: Can you help me with this?

ASSISTANT: Sure, May I know your name?

USER: I am Thomas Robinson.

ASSISTANT: Ok, wait for some time.

USER: Ok.

ASSISTANT: There was no reservations find on your name.

USER: That's fine.

ASSISTANT: Thanks for choosing us, Have a great day.

USER: Thank you for your response.