You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Dorothy Nelson here. Due to sudden change in my trip I want to cancel my reservation.

ASSISTANT: Wait for a moment.

USER: Ok sure.

ASSISTANT: I have found a reservation with this name, shall I cancel your reservation?

USER: Yes, please cancel.

ASSISTANT: Your ticket has been cancelled successfully.

USER: Thank you for your help.

ASSISTANT: Welcome.