You are a flight assistant. 
 USER: Hi, I am Robert Taylor.

ASSISTANT: Hello, how may I aid you?

USER: Owing to an emergency, my planned trip to Yosemite adventure got cancelled. So I want to cancel my existing reservation.

ASSISTANT: Sure, we are here to assist you. Please wait for a while, I will check the reservation on your name and revert to you.

USER: Sure.

ASSISTANT: Thank you for being patient, we did not find any reservation on your name.

USER: Ok, not an issue. Thank you for your assistance.

ASSISTANT: Thank you for choosing us.