You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

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 happy to help you with that. Can I have your good name please to check your reservation status?

USER: Sure, Linda Rodriguez here.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry Linda Rodriguez, no reservation has found under your name to  change.

USER: Ok, no worries at all. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a good day.