You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Please help me with changing my reservation due to postpone of my brother's engagement.

ASSISTANT: Sure, may I know your name?

USER: Reservation was done by the name Joshua Thomas.

ASSISTANT: Ok, wait for some time.

USER: Sure.

ASSISTANT: There is no reservations found on your name.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for choosing us.