You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Owing to an emergency, my planned trip to Yosemite adventure with colleagues has been postponed.

ASSISTANT: Ok.

USER: Can you help me in changing my existing reservation?

ASSISTANT: Sure. May I know your name to check the reservation?

USER: Sure, I had a recent reservation with name Michael Moore.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation found on your name.

USER: Ok, no issues. Thank you for approaching us.

ASSISTANT: Thank you for approaching us.

USER: Thanks for your service.