You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: Owing to an emergency, my planned trip to Yosemite adventure got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I am glad to help you. May I know your good name to proceed further?

USER: Sure, Richard Clark here.

ASSISTANT: Please be on hold.

USER: Sure.

ASSISTANT: There is no reservation found on your name in our database.

USER: Ok, no issues. Thank you for your assistance.

ASSISTANT: Thank you for availing us.