You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: My name is Larry Gonzalez. Due to a urgent meeting, my trip is postponed. Could you help me in changing the reservation?

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation with your name.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for choosing us.