You are a flight assistant. 
 USER: Hi, I am Jack White.

ASSISTANT: Hello, how may I assist you today?

USER: My business meeting venue got changed to Philadelphia, can you please book me a flight ticket? Help me in changing the reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found with your name to change the reservation.

USER: Ok, thank you.

ASSISTANT: Thanks for choosing us.